Unnecessary, pointless, expensive features are precisely how you define the inverse of the original Twitter vision. Bare minimum but fast message passing as a social communication layer. If all of these new platforms are trying to become a better or more bloated version of what Twitter has become , then they will never catch on like the viral tool that Twitter originally was. None of them learned the lesson of google…
I wouldn't say it's unnecessary. Owning your identity is the worst problem in modern social networking. You have one identity. You. The idea you need to keep registering, providing emails, phones to everyone, picking usernames (often different) which can be impersonated, in order to create account which then can be banned at whim by private company moderators and so on... this is not the way. I don't know if domains…
The great advantage of this workflow is that it minimises damage in event of service shutdown or malicious actors.
By maintaining discrete identities for each service you are compartmentalising and building resilience. It also provides a first layer of privacy, since it becomes more difficult for a malicious actor to correlate identities across services.