I think he wants every person to have one and only one account. That seems getting a likely very bad for a potential good to me. I think the notion of non-governmental UBI is interesting, however.
I think it's archetypal VC-think to make the indigent give up identity in exchange for trinkets. That's like Discover giving me a t-shirt for filling out a credit card application. I also think it's appalling that someone standing up a blockchain is using "fraud" as his argument for invasive privacy breach. It's on the fucking blockchain, dumbass. One fraudulent transaction makes every transaction from that address suspect, and every address transacting with that address suspect, publicly explorable, forever. The fact that Sam Altman thinks he needs more data than HHS in order to give people less says absolutely nothing new about the entrepreneurial class.