Just throttle your router settings for download/upload - have fun!

In all seriousness though, people designing websites should be given the shittiest connections possible and old computers (between 5 and 10 years old). Maybe then we'll end up with websites that haven't got more JS than content, broken CSS and images that push the page download over several megabytes.

Chrome Dev Tools let you simulate shit internet connection (2G, slow 3G, fast 3G, etc.) and Google encourages to this for development for the reasons you've mentioned.

It's awesome it exists, but useless if nobody uses it. I think the Google homepage is the only Google product I'm aware of that loads fast, minimal CSS and still loads without JS. Even on a modern computer, some websites have become completely unacceptable to run in the background (i.e. Facebook).

Installing NoScript and blocking external CSS was the best decision I ever made. Now use <25% of the RAM and <10% of the CPU I used to for the same number of tabs (in Firefox) - with a better experience because the browser isn't constantly trying to die.

The UK Government site team is my go to for a good web design philosophy: https://www.gov.uk/guidance/government-design-principles (Hell, if they could run the actual Government like this we would be in a lot better shape!)

Don't forget progressive JPGs, which loads the entire height of the image over and over with gradually increasing detail.

There was also LOWSRC, which is long gone nowadays https://html.com/attributes/img-lowsrc/ https://bugzilla.mozilla.org/show_bug.cgi?id=92453

Shhhh... Or my boss will hear you

You can see images load line by line today, if you throttle your network (either through Chrome devtools, or some external tool). Or just get a dialup modem, you probably have a provider you can reach, and the good ones can be plugged in through ethernet.