I use Firefox sort of begrudgingly. It's marginally less bad than the other options, but it's still an awful browser. I vehemently disagree with almost all of its design decisions, and with every new release they seem to stray even farther from sane UX. It has hamburger menus on desktop and a lot of weird space-saving design that makes no sense on a modern high resolution display. Buttons are small, have cryptic flat…
Looking at the mentioned LibreWolf, the changes reminded me of my time using ungoogled Chromium. I left that path, because it seemed like an uphill battle to keep up with upstream changes in the long term. Also you potentially risk using a somewhat outdated browser until all changes are ported to the new version. I was also not a fan of giving Chromium browsers additional market share.
For me switching to FF was primarily about using a browser supporting user choice and privacy, not for its UX or anything else. However Mozilla is losing my trust in this regard. Opt-out telemetry/tracking/whatever you want to call it and user experiments as well as reducing user choice with forced signatures by a central party, this sounds counter to why I switched in the first place. I hate that I have to go into settings after installing it to disable "features", it is not Windows...
[1] https://support.mozilla.org/en-US/kb/add-on-signing-in-firef... (I am also a bit surprised I had to strip an utm key from this URL...)