I can see your point, but would argue there is a difference. Small independent game designers can at least approach studios for money to fund/produce their game

I can see your point, but would argue there is a difference. Small independent game designers can at least approach studios for money to fund/produce their game. Composers, playwrights, and artists don't have an equivalent body to turn to. If you're not commissioned to make something, you can't sell your product basically at all.