I used Librewolf for years, sadly it's based on Firefox which is both doomed(because Mozilla) and has bad compatibility and way inferior security. The Tor Browser and Mullvad Browser are doomed aswell. For desktop the best browser right now is Ungoogled Chromium, it respects your privacy and has way(way) better security. For mobile Vanadium.
Discussion
fwiw Ive never had a compatibility problem with Librewolf
but I'm a simple fellow that doesn't do a lot maybe
Sites don't look the same with Firefox vs Chromium. Just ask any webdeveloper. Firefox has inferior performance, security, compatiblity. GrapheneOS highly recommends users staying away from Firefox browsers. Even the Tor Browser is doomed.