There used to be a really cool site called PeaceKeeper (by FutureMark) that ran performance tests on the browsers, which I used a lot. I have a feeling they received complaints from companies that didn't rank highly though, because the reasoning they gave for discontinuing it was due to "browsers are now more focused on features than speed", which to me is codeword for "too many companies are complaining."
I've tried to be unbiased when it comes to browsers, I just want the one that's the fastest and has no issues while visiting sites. I think the main problem in comparing browsers is that like gaming consoles (xbox vs playstation) the level of fanboi nonsense is off the charts. Firefox for whatever reason has people acting like it is the best thing since sliced bread, and so one day I went and tried every major browser out there, and put it through the paces in heavy real world usage for a few weeks. I found Firefox's engine to be really bad, the rendering process is awful, and it's just so slow overall. Chromium always outperformed it, no matter what versions I try. I even prefer Edge and Internet Explorer to Firefox. I think most people are finally coming to this conclusion too, which is why so many companies have converted to chromium in recent years.
It's like iPhones, the level of fanboi hype on that crap is insane, it boggles my mind. People will run out and buy the latest phone that now has the new feature of "no more headphone jack". It's pure marketing that sells these things, nothing more, and contributes to why everyone feels the need to justify what browser or phone they use because going against the grain gets you made fun of.