Having switched to Zen Browser, something I miss with Firefox was its stability. I find myself looking up Zen browser bugs and workarounds too much. This is the 2nd or 3rd time I’m downgrading Zen versions due to a bug in the stable version, I never had to do so during my years on Firefox. Devs on Github making an app on their free time have can’t spend as long on QA as a multi-mullion dollar organization.
I have often had to go into about:config to revert unwanted new behavior, but never had to downgrade.
Been with Firefox for years. Just moved to the LibreWolf variant with no issues in my first week. Uses the same Mozilla sync and my favorite extensions still work.
I downgraded Firefox once last year, but after the next major version a couple weeks later, I was able to upgrade again. Never had to downgrade it before that, though.
I forget why, though. I think it was a pretty niche issue.