Well that part of the economy and anything that caters to it might just die.

The whole economy would be whatever AI/robots need: compute, energy, raw materials, software, data, etc.

Why do economies need people? We look at the past and say 'People are labor', but what happens when people are no longer labor? Effectively people live on handouts from people that own AI, or the AI itself.

All those Greed is Good people are going to look kind of silly when a hand full of greedy people fight over everything and leave the rest of us for dead.

+1. soon there is nobody to sell to.

You’ll be entertainers for the rich class. Teen prostitutes, jesters, and caretakers, while they live their best lives.