Without law enforcement, which is centralized anyway, your documented ownership is worthless. So if the state or a similar centralized real life organization, whiches existence people agree on, is needed to grant and enforce that ownership, blockchain is unnecessary. They can instead just store that shit in a database.

And who would the largest nodes on that blockchain be? The banks? Who could say and do whatever they conspired since they command >50% of the computing power and/or value?

The average person isn’t going to build a fucking blockchain node just to keep the deed to their house.

“Grandma, please you need to fill your basement with these ASICs or else script kiddies will steal your house”

It could. It may or may not. I agree decentralization is a good thing, but do governments agree as well? First of all, governments are very resistant to change if that doesn't play into their interests (real or percieved like this privacy violation). Using a traditional database to keep track of ownership seems cheaper (since they already do it) but most of all simpler. I'm not too familiar with the way blockchain functions so I may be wrong, but say someone wants to sell a car. In the current state of most countries you just draw up a paper or fill out a form, maybe get it notarized and pay taxes. A database seems flexible enough that if your sale didn't get logged and the buyer got pulled over and questioned, they could provide the contract and clear up any questions about ownership. Or say the ownership was stripped as part of a court order. If it was a database, then changing the records is simple, but with blockchain the court would either have to get you to transfer the ownership volountarily, force you to disclose your keys or have some mechnism of forcing a transaction from the requester account (which as I understand it seems what blockchain is here to stop abd a core part of the specification). Alternatively the government just uses blockchain instead of a database, managing all the keys, wallets and identities (as in they have everyone's keys and do all the transactions) which is the same level of centralization as a database, but with extra steps.

Ownership was (and is) a social contract, and a flexible one at that. Things get gifted volountarily, sold, taken away lawfully and inherited in a single jurisdiction by the thousands daily, and not all of these are well documented. Blockchain seems very limited in what it can do flexibility-wise which makes it unsuitable for keeping track of ownership, and that's not taking into account that either everyone would have to actively use the blockchain for their sales and be familiar with the technology (decentralized) or having all the wallet keys operated by the government (defeating any useful feature of the blockchain for citizens). Adding blockchain into the mix will just complicate the transfer process and centralize it (as in we either do all validation on the blockchain or none), and with the fact that all the transfer history is centralised in the blockchain (despite it being decentralised in storage, it's still explicitly stored and accessible) it would serve as just another venue of privacy violation and opression.

Maybe blockchain could be useful for things like, say carbon credits, or similar government-issued 'currency', but I don't see it applicable to validating general ownership on a large scale for the general population, ever. The 'digital Euro' proposal, also being blessed by the buzzword Blockchain seems very distopian to me as well. Here, with currency being used I can see how it would be applicable in the real world (instead of heavily unstandardised land deeds, sales contracts and other proofs of ownership you have strictly defined currency units), but this also seems like a gross privacy violation as the government (and maybe anyone) can see where you got your money and where you're spending it down to the cent.