I actually don't agree that is is unsustainable, I was just pointing out the logical falicy. It's a weird thing to say that "paying a person to do a newly unnecessary job is unsustainable", especially in the context of AI. It doesn't make sense to complain about something when the only proposed solution is doing the exact same thing in a more roundabout way.

As the other person was getting at its not a logical fallacy. One is having wasted potential ( workers doing jobs that should be automated away ) the other is capitalizing on that new found potential by giving them the means to survive maybe even thrive if we actually get UBI right. One is unsustainable as you are paying to keep appearances up for no positive benefit, the other frees a market of labor to do creative and inventive tasks that can further humanity and provide even more benefit.