The other issue with all this is when you have the IMF just able to print money.. it makes the whole exercise superfluous.
Proponents of UBI claim it could be implemented through value added taxes, which is done in Europe (consumption taxes placed on a product whenever value is added at each stage of the supply chain, from production to the point of sale.) The amount of VAT that the user pays is on the cost of the product.
If AI and more efficiency takes jobs away on huge scales, paying clients will have less spending power and the economy would stagnate. The abundance that technology will create could be distributed in this way to keep the economy alive and well and people off the streets.
I think the future will be that homelessness etc. will be solved but if you want more you'll have to either be very inventive or be a programmer. I don't think there will be as much motivation to rise above however, as technology is making it so that more money doesn't necessarily equate to a better life.