the reality is that mastodon (as the most developed of the fediverse/activitypub platforms) has missed the boat of the Twitter/X decline. Bluesky's growth has slowed somewhat, but it has already gathered critical mass in various influential communities that mastodon never did.
The important issue going forward is whether there are lessons learned and what the reaction will be. After decades of stagnation the shape of online interactions is now less fixed.