There will be few people needed at the apex of the arts, once the best of the best can do the jobs of most everyone else combined. We still need an economic plan for everyone else.
I think you're vastly underestimating the diversity of tasks to be mastered. Everything is a hard problem if you want to do it well enough, and the current economy consists of a vast number of distinct kinds things made sloppily.
Try googling "in vitro meat" and you may find some answers, but I don't know if this problem is solved yet. This article mentions algae as a possibility:
I agree, there will always be fewer people needed at the apex of the arts, and in fact that's the definition of the apex!
But an economic plan that revisits the idea of what an apex is, I think would accomplish that 'for everyone else'.
That's why the idea of micro farming is so interesting: in an agrarian system where people grow their own food, as a pastime and 'art', then you can afford many, many apexes - at least one per farm/garden.
