Voting and mod tools, to start.

You hear the mods talking about how there are no efficient moderation tools and hoo boy are they not just whistling Dixie. It's difficult to even ban someone.

Voting is so broken because of federation as to be meaningless, or at least it should be meaningless but to everyone else it isn't. So they walk right into another emotional meat grinder, thinking they're being upvoted or downvoted legitimately without thinking whoever they're talking to could just be voting against them with their alts. Users have about 3 to 5 on average, at least from my count of others I've encountered so far. There's nothing stopping someone from building botnets and rigging votes of important issues, misleading the users and enabling the most horrific shit imaginable. Imagine someone using a botnet to upvote gore or CP on servers they don't like. Lemmy.world already had to deal with a similar attack.

Lemmy as a platform just plain sucks.