Agreed that Mastodon 2022 / Bluesky 2025 is far from a precise correspondence! But while fedi's ecosystem is very diverse in some ways (and I agree that's a fundamental asset), it's much less diverse in others. Similarly the ATmosphere ecosystem is very diverse in some ways.but much less diverse in others. So my guess is that most fedi projects have an analogue in the ATmosphere -- not as far along because it's newer, and we'll see how many continue and how many wind up as dead ends.
Of course there are plenty of exceptions. Off the top of my head, I can't think of ATmosphere analogies of Bonfire, Frequency, or the friendica/Hubzilla/(streams)/Forte family. Then again there are also ATmosphere projects where I can't think of any fedi analogy: Blacksky, Gerrm, XBlock labeler, Anisota, Semble (a sense-making app). And some of the ways the ecosystems aren't diverse mirror each other; for example both are very Europe/US/Canada-centric.
@informapirata