@leo The biggest issue with deciding where to join Mastodon is access to the local timeline - the server/instance firehouse.
Currently, there is no method by which one can look at the local timelines for other instances (servers), but since each instance is formed around common interests, those timelines can provide a nice source of curated content… which on Mastodon, might be the only content you have to look at while looking for others to follow.
It’s a huge “growth” feature that’s missing.