We're smoothing onboarding (e.g. choose a server) with things like easy invitations: https://blog.prosody.im/great-invitations/

Support for creating invitations from within the app was recently added to Conversations (sponsored by the Snikket project). I'm hoping to see more servers deploy this functionality in the coming year, and more clients implement support.

Snikket is built around the idea of invite-first for onboarding onto self-hosted servers. As the dev I may be biased, but I've onboarded many people seamlessly this way.