He didn't pay for that Picasso. He paid for a receipt stating he owns that Picasso signed by crazy uncle Eddie. When you buy an e-book you don't pay for "proof

He didn't pay for that Picasso. He paid for a receipt stating he owns that Picasso signed by crazy uncle Eddie. When you buy an e-book you don't pay for "proof of ownership" like with an NFT. When you buy an e-book you get an actual file containing the data of the book. With this file you can read the book. With "proof of ownership" you can do exactly nothing.