One problem is transaction costs; you need aggregators to sit in the middle, adding up the people paying and to be paid out. Structurally, aggregators are then

One problem is transaction costs; you need aggregators to sit in the middle, adding up the people paying and to be paid out. Structurally, aggregators are then in a position to extract rents. Which they will do, sooner or later. There are of course other problems, fraud, money laundering and the like, which extract taxes, and and a whole patchwork quilt of national regulations, which extracts a lot more. Things like crypto look, feel and smell like money laundering. I don't think there's a technical solution here. The problems are social and regulatory.