substantial onion service federation support (and probably I2P too though I've never used it) would substantially reduce the material obstacles to self-hosting
like, if you already have a computer and an internet connection, you can host an onion service without having to worry about TLD registration, DNS, or firewalls. that's super cool
I'm not even just speaking theoretically here, there are instances *right now* that federate with onion-only instances and that's pretty sick tbh