Do you really think the entire country runs on an old copy of Microsoft Access? Databases are routinely replicated and in this case there’s a natural partitioning scheme: your transaction is recorded by your local clerk and replicated to state mirrors. Since updates only happen in one place, each node only needs write capacity to handle local traffic – a huge advantage over a blockchain – and read replicas are trivial.

Put another way, the banking system handles orders of magnitude more traffic with far fewer resources than a blockchain. There’s no reason to think people are suddenly going to start making real estate transactions at a significantly greater volume than credit card transactions.