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I always see these kind of comments, that many sites don't work in Firefox while they do in Chrome. When I encounter a broken site I always also check it in Chrome but the times where it is actually a browser's fault is like once a year. Usually it is some blocking of cookies or something that I have enabled in Firefox. Even sites from Google which everyone seems to describe that they are specifically made to work on…
Perhaps you use Firefox on Windows. Firefox on Linux has much more problems than Firefox on Windows, mostly because it does not support many GPUs, so it frequently disables WebGL or it cannot use hardware support for playing videos, even now, in 2026. This breaks many sites. Unlike Firefox, the Linux versions of Vivaldi/Chromium/Chrome do not appear to have any deficiencies in comparison with their Windows versions.
Whenever I encounter a broken site, it's because I blocked some advertising scripts and the whole thing fell apart with a slew of JavaScript errors. I'm quite happy to avoid such shoddy sites.