It's a nice idea, but major sites still do user agent sniffing. Try setting your UA to one of those strings and visiting google.com -- the SERP looks like it came from 2009.
If Firefox tried that, it would instantly become that weird browser that makes Google look bad. The internet would be flooded with tips on how to set a custom UA that made it pretty again.
Re:Browser Fingerprinting: A Survey
by username223 on Monday May 06, 2019 @02:20PM
(#19842220)
> Try setting your UA to one of those strings and visiting google.com -- the SERP looks like it came from 2009.
I just tried, and it's great! I had forgotten that search could be so snappy and simple. The more likely outcome, unfortunately, is that Google would adjust its UA-sniffing to serve the same 2019 bloat to "Firefox."
This could be fixed with a bit of courage. Firefox could use "Firefox", Safari "Safari," etc. UA sniffing and UA strings are completely absurd at this point, and need to go away.
> - List of Plugins
JavaScript should not see this, especially not their versions.
The last three are harder to avoid for "responsive" web design. One attribute you didn't mention was the font list. There is no good reason for JavaScript to be able to see this. The model should be that the page requests a font, and the browser uses either that or its best try at a substitute.