Many sites are broken on non-Google browsers though. But the advantage of being able to use adblockers in Firefox alone outweight that - not even taking privacy into consideration.

I actually use firefox on android for 7 years or so. never experienced broken sites on it. can you please give me some examples of broken sites?

Thinking about it, only internal time reporting tools. Both on my current and prior employer they only worked with Chrome or IE.

I think I overestimate the amount of broken sites due to the adblocker messing them up, not Firefox.

Tangentially related. Using Firefox on Linux for anything Google chat/voice call related is not a very pleasant experience

You could also consider the Firefox forks Fennec and Mull.

and allows to install an adblocker