Is it time to fork Firefox under a browser-focused organisation? I wish I could donate directly towards the development of Firefox to avoid this kind of deterioration, without funding Mozilla at all.

LibreWolf is a soft-fork in this vein. Notably, it's on Flathub, so it's very easy to install.

=> https://librewolf-community.gitlab.io/

Iceraven is a similar (less mature) project for Android.

=> https://github.com/fork-maintainers/iceraven-browser

It would be nice to have a single umbrella project/brand, which could essentially treat Firefox in the same way Edge and Opera treat Chrome.