It seems to ignore Economics, Game Theory, and Human Nature. I just dont understand how it could rationally be viewed as a workable solution.
From a simple supply and demand standpoint, how does the extra income introduced not simply cause the cost of basic* goods to rise accordingly such that you end up with your UBI increasingly falling behind what is needed to support a minimum standard of living?
* Added "basic" for clarity, I don't imagine this would affect the cost of luxury, or recreational goods to a large extent, but an extra $1000+/month per person would, I expect, have a drastic effect on housing rental rates amidst the lower to middle class residential areas
Now imagine the tribe is really big and named the USA.
Human nature is both social and competitive. UBI is a social gesture, it doesn't take away or prevent competitiveness.