This applies to poker, too - a game where you really can get a consistent advantage over other players with sufficient study and make a living. Once you strip everything else away about the game, you're sitting in a casino for many hours a day, spending as much time as you can with mentally ill idiots... to make less money than you would applying that exact same effort to get good at an in-demand job skill and building things that people need.

Most people who are in a position to make a career out of poker decide that it's not worth it and remain (very good) recreational players. Casinos can be fun places to visit, and tournaments can be a lot of fun, but I wouldn't want to make them a fixture of my life.