As for speed, it would be interesting to have a "surfing contest", i.e., a web surfing contest that is a "browser challenge", pitting a team of users using a no-Javascript user agent versus a team using a "modern browser". The objective might be something like a race to interactively extract a given item of textual information from a selection of Javascript-heavy websites.
Indeed it would be and as far as I know it's not been done recently either (anyway not with openly published results). Nevertheless, I would like to see say the top six browsers tested on heavy JavaScript websites that use lots of advertising. I'd reckon 100 sites would be plenty to get a definitive outcome of the speed differences.
Of course, it's unlikely happen given the fact that JavaScript is now so ubiquitous along with the all-too-common assumption that the web cannot cope (or would cease to work) without it—the logic being that there would be little point to the exercise. Moreover, if a such a test were conducted and nuking JS showed that most sites would be much faster without it then it'd still receive negative publicity as the many naysayers would point to website features that didn't work. And that's absolutely true some features will not—and with some, albeit still fewer again, will not work at all.
(Remember, this used not to be the case 20 years ago. So it's time we examined why JS is so critical now when it once wasn't. I'd make a substantial bet that the real or most substantive reason has little to do with improving the experience of website visitors (that is unless one considers that slowing websites down as a benefit) - and it's much more to do with benefiting website owners and their advertisers. One thing is for certain, we really do need to put a proper measure on this. Then, like limiting the advertising on television (as most counties already do with (essentially) the exception of the US), with accurate stats legislators could apply appropriate limits on advertising and data collection, etc. to web services. As things stand at present, it's nothing other than the Wild West.)
Of course, the test sites would have to be selected fairly and with care to provide a representative sample. I tend to gravitate to sites where JS is minimal and where killing JS makes little or no difference to viewing the core material (many technical sites fall into this category). Therefore, taking say the last 100 websites that I've visited would not be a representative sample. Incidentally, of the sites I visit about 95% work very well without JavaScript—so my default experience is to browse without JS enabled. Of the remaining 5% I've a choice of what to do, I can either toggle JS on and refresh the browser or instantly get out of there. On average I'd back out of about two-thirds of that 5% and toggle JS on for the remainder (all up, that's around 2% with JS).
This is where the naysayers miss the point. Whilst it's possible to default JS to off at the beginning of a new session I usually don't bother, so it's not unusual for me to start a new day's browsing with JS still toggled on from the previous session without me initially realizing it. However within a second or so I know that JavaScript has been left on by the way the browser responds (anyone who does what I do will know this experience well). Even if no JS content is obvious or visible on the page, if it's running tasks in the background then I will almost certainly notice it immediately as the browser is less responsive, paging becomes slower and there's a jerkiness to it that's not dissimilar to running programs under a Virtual Machine). I know JS aficionados either won't believe me or that they'll claim I'm exaggerating. Moreover, I know that me saying that I'm not exaggerating or attempting to prove it won't convince them one iota whatsoever, so there's no point in me trying—and then I don't have to prove anything anyway! If anyone really needs to know then he/she needs to do a quick survey of others who don't use JS and they'll soon find that those non-JS users will support what I'm saying.
"they have acquired a remarkable sense of entitlement. (The search still works.)"
Right, this is a good indication that the code that's actually been killed is the monitoring or spyware stuff and the coders/website owners are indignant about the fact that it isn't working (after all, given various error messages we get in these circumstances, we know they're checking to see whether the code in this section is running as intended or not). I regularly get messages such as 'Please turn on JavaScript to get the full benefit of this site [and or] certain features of this site will not work without JS' - and that's true—but they are the very ones that I do not want to work!
You often see the same nonsense with Android apps. Like the PC, I turn off as much Google as I can. I do not use any of Google's services, so on my rooted smartphones this means removing all Google apps (Google Play Services, Play Store, etc.). When the Google apps are removed many Android apps will complain to the effect: 'XYZ app will not run until you update Google Play Services' but they still work anyway (there are many exceptions that won't run and how to get around the problems is too off-topic to discuss here). Anyway, when apps still work but complain about Google Play Services it's almost a certain bet that it's the data gathering aspect of the Play Services that's relevant here—so I just ignore it (most people, even diehard Google fanatics, would prefer that data-gathering didn't work). FYI, always keep your old APK app files before you upgrade (and don't overwrite APK backups, as often that message doesn't pop up in older versions). That's to say, often Android updates contain nothing other than more highly refined code for spying, ipso facto, with Google Play Services and Play Store updates. (Of course, you'll get the security spiel/reason—as that's always the mandatory excuse/justification. Let me put it this way, you'll likely get both security updates and told so, what you won't be told is that Google's Android's Google Play Services 'receivers' schema has also been revamped to collect even more user data than previously (Android experts, I know that's a shortcut explanation/oversimplification but it'll have to do).
In my opinion a better and much more relevant and informative test would be to do a survey of a larger number of websites, say perhaps in excess of a 1000 or more of the most popular ones. Then analyze exactly what JavaScript is being used for on each site—that being to do a detailed statistical breakdown of JS's various functions on a per site basis then average this breakdown analysis across the whole web.
I've not conducted a rigorous test like this myself as it's a great deal of work to get meaningful statistics but I know from the number of times I've looked at the code from heavy JS sites that a very large percentage of the scripting goes into alerting every dog and sundry about what users are viewing and or doing. Whether one analyzes the website code or logs the destination IP addresses these pages call home to, one will see the huge amount of feedback that's being sent to many, many dozens of data-collecting websites. It's quite horrifying to watch it happening (I've been so alarmed that it's not the first time I've pulled the RJ-45 plug out of the PC socket to stop it continuing).
Once employees are also targeted and held responsible for their actions at law then we stand a chance of getting at least some of our internet back.
Google, Facebook and their cohorts are outrageous, they have been stealing our internet with complete impunity for over two decades like a metastasizing cancer. We users really do need to get proactive over this, if not then soon the internet will be effectively dead for many of us—we'll be left ghettoized in some outpost or alternatively we'll be forced to abandon it altogether. We may even need to resort to street demos or marches to convince politicians that the rotten, monopolistic behavior of Big Tech is no longer to be tolerated.
It's also time we banned non-human entities (aka corporations) from lobbying politicians in private. Any lobbying by them ought to be done at public hearings specifically held for the purpose (corporate lobbying has probably done more damage to our Democracies since the Civil War or even earlier than any single other factor.)
"As someone who routinely uses a browser that does not support Javascript,<...>"
Likewise, my browser has JavaScript turned off by default. 1vuio0pswjnm7, what you failed to mention was how much faster webpages render without JavaScript, when it's switched off the speed improvement is enormous, also all that jerkiness and unevenness of presentation disappears. (As I've posted many times, it's not JavaScript that's the main fault-it's the enormous abuse websites commit using it. It's nothing nowadays for a webpage to be anywhere between 2 and 5MB in size, and on inspection a huge percentage of that code is devoted to serving up you private data to surveillance capitalism. Reality check: remember a standard page of text is only 2kB!)
"Javascript engine has zero effect on the browser's ability to display the information I need from the site. And I still get the info 100% of the time anyway, if I really want it."
Exactly right! Take note website owners who present blank pages when JavaScript is turned off: I used to find it a challenge to get your pages which I then proceed to do anyway. Now I no longer bother, as I've learned that websites that use such scummy lowdown tactics aren't worth visiting anyway. From my observation there's a remarkable correlation between such behavior and the [lack of] quality of the material on the website.