5. The cost of storage
Users therefore pay to store their data in the BlockChain. And then, this data is maintained for eternity. Does that make any sense? This means that miners have to bear the cost of this storage indefinitely. In fact they rely on later users to finance them permanently. And as the BlockChain lengthens, they have to store ever more. Depending on upcoming users to ensure the future of storage has some points in common with a Ponzi scheme. If users move away from a given BlockChain, miners stop maintaining it, and the stored data is lost.
But the only one who has a stake in storing his data is the original user. It would be more consistent to make him rent storage than to make him buy the entry fee into a register whose maintenance will then have to be financed by others. It would also be consistent if, in the event of non-payment, the data entered was deleted and the space it occupied was freed. But this is PeerStorage.
6. The burden of proof
Take the example of a real estate sale: the seller holds his property deed. This deed includes the history of the property, itself composed of all past transactions, and where the last buyer is the owner. The notary checks the deed, the identities of the two parties, then adds a new transaction to this history: the sale contract where the last owner (the seller) and the new owner (the buyer) appear. The owner of the property, and only he, is always in charge of maintaining this deed of ownership. He alone has an incentive to prove, if necessary, that he owns his property.
In this case, which can be generalized to all kinds of transactions, only a few people (at least one) have any interest in maintaining the history about them. What guarantees authenticity is not the plethora of copies, but the successive and verifiable signatures of all the previous owners who at a given moment signed “sold to”.
In this respect, the usefulness of maintaining a single and thousands of times duplicated register of all transactions that have ever taken place for all users is questionable.