I moved to Lemmy over from reddit not because of content or better UI but because people behind reddit seems like jerks to me and i came to realization I'd rather use open source.
What i lack here is information e.g. programming communities in Lemmy are, well, dead. If left on Lemmy things that are "recommended" to me it's sensational "news" that are aimed to spark woke vs others battle in discussion.

So what to make better ?

• to build what reddit has, I'd call it a content library and i don't care if it's done by bots or humans. For me the facts + discussion to ask question is super important.
• if searching for a topic outside of Lemmy> Lemmy doesn't show up in search engine but reddit does. Some optimization needs to be done to get better score at search engines.
• let users to block instances and thus make de-federation to user's decision.
• i think there needs to some kind of cross instance community, i don't think having same kind of community in multiple instances with different content is good solution.