If we're trying to define precise terms here, "free market" and "capitalism" don't overlap at all. Capitalism is a type of government, free markets are a (group of) polic[y/ies].
I don't see where the logic of your comment comes from either way though - capitalists are typically in favour of a free market, no? And typically the "purpose" of a free market is accruing wealth as part of a private enterprise?
Free markets are sometimes useful tools in making profits but are also sometimes hinderences towards being able to extract the highest amount of profit from consumers.
That's why we see so many mergers and intensive lobbying for government regulation in things like healthcare, telecoms, and air travel, it's way easier to make money if you can restrict competition in your market and it's something essential to consumers
