| Double spend was solved by the use of cash money, not the financial sector. If I give you a coin (or paper money), then by definition I don't have it any more. I can't spend it twice. Accounting with transactions netting to zero ("double entry") solved the problem of recording transactions in an immutable way on a ledger, assuming you control the ledger. Clearing houses solved the problem of interparty risk when settling (by using an intermediary that controls the ledger of transactions between parties). Title registries solved the problem of "ownership" by creating the concept of a "title" (ie a government backed identification of property that is recognized by law that the bearer "owns"). Title registries (like "Torrens titles" invented in Australia) solve the bearer problem by having a central ledger of title holding. Blockchain can "solve" the ledger parts of these elements. But the ledger being immutable doesn't solve the problem of recognition of title (see NFTs). By adding the machinations of "mining" and "proof of stake/work", blockchains can be extended to include the "title" as part of the ledger itself. The mining transaction effectively creates something that is initially owned by the miner. Ethereum adds to the "intelligence" of the transactions stored on the ledger, adding elements of computation to each one. All the rest of it, all the invented coins etc, the "exchanges", etc etc ad infinitum are attempts to map these ledgers back to fiat currencies so that "actual" money can be made. |