> if you have no government, the housechain could be a way for a decentralized society to implement the concept of a land registry. Once everyone agrees that the housechain is proof of ownership, then measures can be taken

Once everyone agrees on anything, they can agree to have a centralised real estate ownership registry. Or a whole centralised government.

Your idea seems to be a thought experiment with weird priors. (Feels like that makes it rather meaningless.)