I've had numerous performance and memory issues with Firefox but from my testing over the years it's the closest to Chrome/Chromium you can get.
Also Firefox gets new features fairly regularly. It's still an "innovative" browser, as opposed to Chromium which is mostly stagnant. Vertical tabs are pretty cool.
If that's where Internet advertising settles, then I might actually be OK with that. And there's plenty that I'm a long way from OK with.