You make an interesting point, but I’ll try a different tack. In all of your examples, you’re using the example of someone trying to falsify who is doing the selling of something, or alter the existence of a record of ownership. But, what about a way simpler example: you have a blockchain record showing you own a bottle of Pepsi. I add an entry showing that you sold me the bottle of Pepsi. In this case, it’s not the blockchain that prevents the fraud, it’s whatever verification process is built into the app we’re using. Yes, the blockchain prevents us from both owning the Pepsi, and that’s good and built into the tech, but it’s the external sources of truth that the app reaches out to that prevent me from fraudulently taking ownership of your soda. That’s all I’m saying—that blockchain is cool, but it’s not a fraud-proof system. And in the worst-case scenario of total systemic collapse, the new government just makes a new blockchain, and goes “maybe you should have had a hard copy, now go farm beets.”