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.
I feel like the functional differences between instances are:
When I first immigrated here, the most popular platforms were Lemmy and kbin. I liked the kbin interface more, so I started on kbin.social - which folded after a while. So I switched to fedia.io, which runs mbin, a kbin fork.
None of this has anything to do with “aligning a personal identity with an instance.”
well… yes and no. you want an instance whose federation and moderation policy aligns with your personal philosophy on those things (and may require you to run your own). so when people see your username, they see the server you’re on, which communicates to them your philosophies on those things.