If you are on Linux I think you will find interest in Konform Browser, which started as a fork of LibreWolf addressing some of your pains. Am dev so please allow me to shill for a bit.
Specifically to your comment:
ResistFingerprinting is IMHO way overkill and breaks nice things like automatic dark modes just for preserving privacy in the 0.001% of cases where browser fingerprinting matters
Konform can respect user theming preferences and dark mode even under Private Mode / RFP.
Firefox Sync,
While Konform still keeps it off by default, it allows configuring endpoints for a self-hosted or third-party Sync server from the Preferences without having to dive into about:config.
Besides that, it goes even further than LW in disabling built-in remote connections, snoopware, and AI integrations.
I hope you might consider it <3