Firefox has had poor stewardship for quite a few years now with an uncertain future.
Even moreso - uBlock Origin doesn't block the modern equivalent of pop-up ads unless you manually block elements. Even then - half the time the block isn't even saved and needs to be redone every page visit.
This is a parallel argument to the whole "to big to fail" nonsense and not really in line with the famous comparison of a single person to a machine. Company strategies are typically created by small groups of people who - especially in this case - know exactly what the impact and longer-reach implications of their decisions will be. It is entirely reasonable to hold the people of any organization accountable for the policies they enact via that organization.
Firefox still allows uBlock origin, and even on mobile.