Think about the experience new users have.
I bring this up a lot, but among the things putting people off from sticking to Lemmy, the new user experience is just not great. I'm not talking about choosing an instance, I'm talking about the general attitude Lemmy has towards content in the feed.
I know it's a very popular idea that if you don't like communities or instances or users, you can block them. Unfortunately, most social media users aren't interested in spending a couple of hours curating their feed to make it useful for them. People are coming in to a feed full of a growing number of niche porn communities, and if they can sort through that, they find heavy-handed political messages, FOSS bros telling everyone how popular software sucks, repost bots with zero discussion, and small community moderators desperately posting dozens of links into the void, hoping for bites.
At the very least, Lemmy needs a sort algorithm that is capable of keeping a page of the feed from being dominated by one community. Going further, I think we could benefit from giving instance admins the tools to curate a default feed that appeals to a wider audience of users.
Maybe then the smaller communities would have a shot at growing.