Reddit also has the problem that if someone makes a community and starts moderating like a dinghole, it can be hard to get people to join one with better moderation.

With federation you can have the same name multiple times, so when people search "[hobby]" they can see all of them.

Then you could have a merged view of all the [hobby] from different sources, and if a mod who arbitrarily decides to interpret the rules unfairly or err on the side of permanent bans without discussion, warnings, or recourse, you can at least still interact with other [hobby].