What do you think is the biggest issue with Lemmy?

Not just Lemmy, but all Fediverse frontends: it's confusing and cumbersome. I've been here for 2 years and I still find that it's very much lacking in the "user experience" department. I have add-ons and scripts to 'patch' things that ought not to need patching. I don't know if it's possible for this to happen given the nature of Fedi, but it should be the case that a new user would find it works more or less the same as non-Fedi software and not have to juggle instances and type hideous and long URLs into the search bar. Instance names and stuff like that should be available to people who want to see them, but by default there's little reason to frighten new users with it. Make it be under-the-hood type stuff. One follow button that works for your home instance regardless of where you are on the Fediverse would be a nice start.

Also, privacy needs to be handled better. Again, not sure if that's possible because of the nature of Fedi, but Lemmy should make users feel more secure than reddit or Twitter, not less. Like, it's bizarre that reddit protects my privacy more than Lemmy does, given that reddit doesn't really protect my privacy much at all.