The fact that this is needed is an undesirable outcome of federated protocols, I believe matrix also has this fault. A good way to look at it is how it is simi

The fact that this is needed is an undesirable outcome of federated protocols, I believe matrix also has this fault. A good way to look at it is how it is similar to email and moving between webmail providers. But therein is the distinction between decentralized and federated. In a perfect world, my identity is owned entirely by me, independent of any central server. If I choose to have a different server host my data, all there should be needed is for both servers to authenticate my identity and confirm my transfer authorization and sync would be seamless. A read-only replica server should also be possible (selfhosted or random servers). I don't knoe the technical reasons why they don't do this.