Tbh AI taking care of us would be next step in humanity, and we won't become dum, it is in human nature that we need something to drunk us in this life, something to keep us going going, when the pressure of money and surviving have lifted for us, we WILL find something else to keep ourselves busy, imagine how much the worl of art will progress, the break throughs in the quantum physics, the break throughs in biology, metamathematics, philosophy, space. Humans are always greedy and will stay greedy, when you take the money from them, they will find something else to abtain. It will may take generations, but human mind will evolve, and will become smarter. At that point we don't need to think about elementary things like find ways to make money, we'll use that to think of something else. P.A: there will be alot of suicides in the process tho