The EU is trying to push the elements of something similar:
Mandatory GDPR data exports
Right to be forgotten
Requirements for platforms to interoperate and allow easy migration
However, I don’t think we, as a society, are ready to have a unique “Earthling object”. People are complex beings, and whatever they say or do when they are high or depressed, doesn’t necessarily represent their professional or family opinions and behaviors (sometimes it does, others it doesn’t). Multiple personalities linked to a single object, would still allow tracing back from any of them to all the others. I don’t think society at large is ready to be accepting and tolerant of more than one personality per person, they even clump past with present behaviors, as if no person could ever change their point of view. What’s even worse, is that personality changes are often gradual, so a person with personality A who evolves into personality B over the course of 20 years, will still be linked to whatever they did or said as the personality A that no longer exists.
While a technology to simplify the self-custody of a multiple-personality object would be welcome, I don’t think anyone, definitely no server, should have access to the whole of it. I’d see it as a lesser evil to have people lose access to some of their avatar/personalities, than for any single entity to be able to cross-reference them and ban a person world-wide.
This is also why I’m really wary of Sam Altman’s Eyeball project. Under the guise of being able to distinguish AI from non-AI works, it’s creating such a unique “Earthling object” able to link everything a person ever does.
Similarly, while I don’t oppose a government issued ID as a means to ID oneself while dealing with the government, I do oppose the idea of “real identities” like what Facebook is enforcing.