There should be a kind of “sorting hat” personality test to attract the interest of prospective Lemmy joiners. People who love solarpunk stuff, for example, would easily find their home in slrpnk.net. Set a link to it on sites like join-lemmy.org to make the fediverse more approachable to casuals.
Yeah I see your point. How easy would it be to sort a thousand instances automatically? Sure you could limit to the top instances, but smaller ones can be niche and I think you still need a way to recommend them. New instances also need a way to work their way up to being recommended.
A sorting hat would be cool but sounds like a lot of manual work!