I've been contemplating this idea for a few years now. If you have fully digital currencies that are completely unregulated and can be used programmatically, it seems obvious that the missing puzzle piece to a valuable product is a standardized API economy that can transact via this currency. But I've been talking about this up and down the Blockchain space but I'm still waiting for a proper solution to this.
There is nothing I can put in front of my Rest API that it starts earning me money, no marketplace to advertise that my API accepts WhateverCoin for the calls..
Once that is done, you wouldn't even need AI mostly, it would be sufficient to even just speed up the normal API economy.