I do that (100+ tabs open at any given time) due to my work (research tends to take up a ton of windows) and because I'm too scatterbrained to focus on a single thing at once, but even then I find that Firefox is really good and arguably better than Chrome. Maybe Chrome has improved since I switched over, but Firefox uses significantly less resources than the Chrome that I remember

When people say oh firefox performance is like so intolerably bad that they HAVE to use a chromium based browser, I always wonder what device people are using and how many things they got going on in the background. I don't understand why ANYONE would need to have like 200 tabs open at once and even if Firefox is slower loading source heavy stuff by like a second, I think that is a sacrifice worth making.
Personally Firefox has been perfectly fine for me even when Im running it on a Win 11 virtual machine on top of Linux that also has Firefox with 10 tabs open and like five other applications in the background on a very mid range laptop.
save