As a desktop Linux user, the thought of Firefox going away is frightening.
Putting aside Mozilla's own lack of direction, what really perplexes me is why there's so many projects dedicated to fluff like desktop environments but almost zero motivation for a good browser/fork. RedHat/IBM seem to only care about the cloud, so there's no hope for Epiphany anymore. Canonical is busy trying to snapify everything to ensure we turn geriatric while waiting for snap packages to load. System76 wants to build yet-another-gnome-alternative instead of doing something sensible like donating to the Librewolf project.
Seriously, if/when Firefox dies (they've started working with Satan/Meta, so it's pretty close I reckon), I'll probably just ditch desktop Linux for home use and move to iPadOS (personally not a fan of MacOS, which I use at work) and Safari or something, because the only alternatives on Linux at that point will be reskinned Chrome alternatives like Brave, ugh.