One of Mastodon’s biggest issues is all the whiny motherfuckers

It's not, they have their own system.

AFAIK, Bluesky started on ActivityPub at first, but then it was decided to make a new protocol which resulted in Atproto. It also started as an internal project at Twitter, was funded by Jack, but then as it got popular amongst a more regular audience, he left when he kept getting pestered with @ mentions and anti-crypto stuff. He hangs out at Nostr now and from what I've been told, isn't really involved in Bluesky's meetings.

There was an effort to bridge Bluesky/Atproto, ActivityPub and also Nostr together - Bridgy Fed - for when Bluesky started getting their protocol federating outside its own network. The issue was, the creator made it opt-out rather than opt-in. The AP fediverse collectively shat themselves, spreading their delusions about Bluesky, one guy called the creator a rapist for using public data and another threatened to sue/fine the creator. It was absolutely bonkers and that incident exemplifies a good part of why people find the fediverse to be toxic, moreso than anything involving Threads.