More granular moderation tools.
But in the last dev AMA they made it clear that wasn't a priority. Honestly it killed a large chunk of excitement I had about Lemmy. Without ways for mods to keep the communities free of shit heads the communities won't be sustainable and will stop growing.
You can still be shitty in those communities too, but with better moderation tools other people who want a space without bigots and hatred can still maintain those. So we can have both, right now it's mainly the shitty people that are happy. Which is not good for building lasting communities.