Just last week, we found out that they sat on a severe vulnerability for 2 months, only bothering to patch it after someone used it to try to pwn Coinbase[1].
I use Firefox everywhere. I tried Chrome recently and it feels a lot faster, but in the end the ability to block ads and trackers (everywhere, including mobile which is where I do most of my browsing) is more important than a bit of speed. If Firefox is fast enough, then faster is pointless. But as can be seen in this thread, some people believe it's their duty to look at ads so for them the extra speed is probably a nice bonus (and perhaps partially compensates for the extra work their browser is doing).
It's been years people suggest the same "have you tried recently", but it doesn't come even close to the snappiness of any chromium based browser when I use it.
Have you tried using it recently? The quantum rewrite they released last year is incomparable to the previous releases. I use FF at home and Chrome at work and I can tell you that there is no noticeable difference in performance. The only time you'll notice the difference is when you use google apps that are written specifically for Chrome, but I personally prefer to avoid trusting the biggest adtech company in the world with my personal data. Plus, FF supports vertical tabs, Chrome doesn't.
