Mutli-account containers is really a game-changing feature for me. I switched from Chrome back to Firefox about 3 years ago (even before containers were available) and at this point there's no going back. I keep chrome around for some sites that require it, but that's it.

Now how do I get Chrome to stop auto-installing itself in my login items on macOS everytime there's some kind of update.

Edit:

Also, if you're on Android, set Firefox Focus as your default browser! It's amazing to not have to think about the tracking consequences everytime you click a link somewhere on your phone. It's basically a new "container" for every link click. If you need the cookies, then there's a handy "Open With" menu to let you re-open the page with regular Firefox, or Chrome.

And uBO works on the regular Firefox Android browser.. Again, game-changer for me.