The free market is a myth, it was a thought experiment dreamed up to explain concepts like supply and demand; in essence the free market is the economics equivalent of the perfect sphere in a vacuum from physics.
No market is free, it is subject to external manipulations by those with control over market forces. This is why cartels and monopolies are considered so dangerous, having sole or co-operative control of an asset allows for outsized control over the markets themselves.
On a smaller scale, an individual person with, say a trillion dollars, still possesses an outsized impact on economic activity. They can buy out competitors, suppress competition, and restrict supply. The less talked about monopsony.
And in a society where civic interests are closely aligned with capital interests, those with sufficient capital start to exert control over social policy, empowering the towards deeper exploitation, and limiting the ability to impose regulations; further weighing the scales in the favour of the wealthy.
A healthy market is not one that is free, it is one that is regulated by a body independent of capitalist interests, that can compel obedience from market players. Without that the bourgeoisie are free to enrich themselves to the detriment of everything.