I have been using Firefox since the release of Firefox 57 aka Firefox Quantum in 2017. I love the browser and most of sites run well in firefox. But there have been a few cases where I had to use a chromium based browser.
Firefox + Ublock origin is a great and awesome combo.
I also use Firefox on android. It is okay, but I sometimes feel it is slow at loading some sites. But it is not a big deal.