Firefox android extension support went from "all" to like "5 chosen ones, but we'll enable all of them very soon" in mid 2019. How and why those were handpicked, who knows, clearly extensions weren't enabled by supported functions at the time. In the usual mozilla fashion that "very soon" turned out to be multiple years.
Importantly, during this entire multi-year gap, nearly all of them worked just fine but it was gated behind an AMO account for... I don't know what reason.
If it was just an experience issue because like 5% failed weirdly or had bad performance but they couldn't validate them all: that's basically fine! Hide it behind an about:config flag! The AMO requirement was a privacy-invading piece of nonsense that had no business existing.
Again, it's easy to imagine answers to these questions and to grasp what is happening. Instead people choose to play the sport of tearing things down, no matter the effect on the people involved, Mozilla, the open web, etc.
Again, Mozilla had a long time to answer these questions (if they had a good answer). If you leave people to imagine things then don't be surprised if they don't follow your PR-sanitized version of events.
If mozilla cared about the open web they would immediately distance themselves from Google and reallocate funding from their CEO's family to things that actually matter for their mission.
