There is no such thing as unfixable. It's just kicking the can down the road. Look at how email devolved because of the features that made spam "unfixable". I would like dns not to go down the same path, which seems all too likely if nothing is done. Already most corporate networks are blocking most "new" domains. It's only a matter of time before new domains you buy are essentially unusable.

such decentralized systems would have to rely on a DHT and the domains would be public keys, somewhat defeating the purpose of a domain.

an effort to do this: https://github.com/pubky/pkarr