Personal preference I guess. I've tried Firefox many times over the years and always ended up going back to other browsers. I find Firefox doesn't render some pages quite right, the user agent stylesheet is odd, and the UI is less streamlined. Performance also used to be a problem although I hear it's caught up now.
I used to be a Chrome user but now I prefer chromium based alternatives like brave and edge (which incidentally, uBO will keep working on). Chrome is still required for work, but uBO change won't be an issue I think, there are plenty of other ad blockers that will work with MV3
I tried it out for a while and yes, it really is as bad as the article implies. I gave it a fair chance for a few weeks and then went back to the old assistant (a task which which gemini was also completely unable to help me with, at one point even gaslighting me and saying I wasn't using Gemini).
It's kind of crazy to think about but it seems like Google is just somehow really terrible at AI