Comment by prisenco

In a federated system, the best you can do is a soft delete request, and ignoring that request is easier than satisfying it.

If I have 100 followers on 100 different nodes, that means each node has access to (and holds on to) some portion of my data by way of those followers.

In a centralized system, a user having total control over their data (and the ability to delete it) is more feasible. I'm not saying modern systems are great about this, GDPR was necessary to force their hands, but federation makes it more technically difficult.