Capitalism is an anathema to Marxism. Capitalism is not about equal outcomes it is about bolstering the successful. In America, capitalism is held at bay by guaranteeing equal opportunity, not equal outcome. Our constitution guarantees that. Only in America can we see people rising from essentially nothing to great success. That's why people flooded our border when Biden stopped enforcing it. You are correct in that capitalism requires boundaries, that is what our Constitution does. It's not perfect but it's way better than any Marxist alternative.