The overhead of disabling every single AI-first change in Firefox is already starting to weigh on firefox-forks.
My view on this hasn't really shifted in the last few months: unless an existing organization, with strong principles, steps forwards and commits to a hard fork I don't really see a future for Firefox.
(I think there are probably only 1-2 orgs with the combination of experience / maturity to actually pull that off, and none of them seem to be even considering that kind of future)