Mastodon is, like, fine, but it has one gaping flaw that makes it utterly unusable for me.

Basically, the issue is you cannot be assured that any particular instance contains the entire conversation thread/replies, because they're not necessarily sent to every server participating in the conversation.

Bluesky fixes that by the 'firehose' feeds federating out to the PDSes and providing complete reply chains, which just flat out makes it a better experience since you can actually see what everyone is saying, not just what people on servers you might be following already are saying.

It's a giant stupid flaw in Mastodon (since other AP based platforms such as, for example, Lemmy don't have it) and really should be addressed since it makes the platform darn near useless since why am I following people to only get half of what might be a useful thread?