actually though? storing a very small but important info (public keys, domain ownership and such) would have been a perfect use case, which also keeps the chain small...

Same thing though, you have to give your wallet public key out of band. There's no other way to prove it's you.

Did you just recommend actually using some kind of crypto and blockchain on HN?

TLDR: That sounds like it is some kind or grift.

In all seriousness, google the Sidetree Protocol. Daniel Bruchner promoted it at Microsoft. And now we can even do zk-rollups too.

Where was I? Oh yes, some kind of grift!