This is very true. I was involved in the NYC art market for about a decade. The smart artists either became professors or started over in a new career. Most of my art world friends are now programmers, lawyers, etc. A very small number of the people I knew actually made it, most of whom had a social or financial advantage to aid them. I knew exactly one artist who briefly made it on talent alone, and he was the art making equivalent of Lebron James.