What do you think are examples of great art? Surely you don't consider Black Panther such? Because I don't see any great work of American art as a poster child for capitalism. On the contrary, the less financial considerations are a part of the equation, the less burdened it is from profitability, the greater art becomes.
Personal gain can be just as suffocating to art as "being part of a collective." When you start figuring profits, target demographics and focus groups in art, it becomes by the numbers.
For every anecdote you bring up, there are counters. Take a look at the Soviet animation studios vs US in the 20th century. US animation was targeted mostly towards children, it was cookie cutter, with big studios like Disney and WB churning out cookie cutter animations with reused frames and characters and cheap serialized shows for easy consumption.Whereas Soviet animation wasn't always easily digestible, often abstract, tackled all sort of adult themes, even philosophy and they all had unique and inventive art styles. Not always pleasing, mind you, but creative.
In the Renaissance period, people made great pieces of art, such as paintings and cathedrals, commissioned by feudal lords. I would hesitate to give credit to monarchies for being nurturing of art. People will find a way to express themselves despite the constraints that society places upon them. And great modern artists make indie films or music, or paintings, or sculptures despite capitalist society's pressure to make a quick buck. So giving capitalism credit for an environment that fosters art is a strained comparison.
If you are such an individualist, give the individuals credit for their art, not economic structures.