Genuine inquiry . Maybe I am not experienced enough with the various federated platforms but I am an avid user of matrix, and have dabbled in lemmy. From what I have seen is federation is on the path to decentralization but not fully there. It creates fiefdom, little kingdoms . Great yes you may find one that suites you better, but users now can end up isolated to their island, switch island sure but now you are isolated for the previous island and maybe others. Its stupid. On matrix you need to know the other island(server) to even find its rooms(communities). Some rooms block users from one server while others block users of other servers. You either have to run multiple accounts or accept the limits. Add in you are at the mercy of your home server, you can lose your account have it immitated, and more. The performance is horrible not sure why, but content is slow to update and spread. Matrix has the problem because of its design most people are on the matrix.org server and so the point of federation is largely lost. They are moving to p2p where it seems the solutions for federation now dont apply.
Anyway why is federation not stupid? Are these problems only with Matrix? Cause I look at lemmy and it seems far worse.
Instance blocking and user blocking are features, not problems. Most users want to block trolls for example. If you dont like that, you can make your own instance without, or just go back to commercial social media. The rest of your rant seems exclusively to Matrix, not Lemmy. I think you should spend more time here (or on another instance) before you really judge it.