The kid has it figured out early on. Kudos. I'm not really sure that the Millennial link is more than coincidence though. Plenty of people in their 30's and 40's doing basically this too. Getting by, having plenty of money, and doing something they love. It's kind of like retirement, except you still have to produce something in exchange for money. But is it really work if you make money singing, dancing, or crafting things (assuming you love doing these activities)?
Two families that we are friends with in our neighborhood do exactly this. They aren't rich but are far from poor. In one family, the mom is a singer (rockstar!) and then works with her husband in their design studio. They apparently landed a contract with an indie movie making props, among their other projects (fabric creations, public art, custom furniture and fixtures, repurposed old stuff, etc). That sounds way more interesting than selling your soul as a consultant and making somewhat more money and then retiring very early (my path to doing whatever I want all day). Although I'm not artistically talented at all (unless you consider my writing "art").