Blockchain isn't anywhere near as useful as a hammer. If you were gullible enough to fall for the promises of the blockchain, then of course you're going to be disappointed that AI isn't a get-rich-quick pyramid scheme that will make you millions of dollars without any investment of time or energy or original thought, because if that's all you're looking for, you're going to be continuously disappointed (and deserve to be). There's a lot more to AI than to the blockchain, and comparing the two as equal shows you don't understand what either of them are.