See also here.
BlueSky users: Guess I'll just come back later
The end
Stop believing that it will convince people to switch to the less user friendly alternative. You want users on your service? You make it as easy to use as possible. No instances bullshit, one page to sign up and access it from a browser,, multiple apps to access it using the same credentials.
The. Same. As. Centralized. Websites.
Make the experience the same as a centralized service, decentralize the backend as much as you want, users don't give a fuck about that.