That's laissez-faire capitalism. It always devolves into an oligarchy, as that's the only logical endpoint of runaway capital. Free markets create the material conditions that lead to them becoming captured and unfree.

This is exactly the answer, and it's why so-called "libertarianism" is not just naive but destructive (and end-result authoritarian) as an ideology: it has a fundamental misunderstanding of what the "free market" actually is behind the scenes, imagining it as some sort of neutral/neutralizing / democratic mysterious force that prevents accumulation of power and being in opposition to "the State" when it is the opposite. "Free market" systems create the State and then dominate it and the interests involved create power systems for their own accumulation of dominance. And the end result is oligarchy.

The counterveiling force has to be an organized working class that uses unions, political parties, and democratic force to take back at least some control of the state and market and force its use for social means. And this is a constant battle. If we start to lose, which has happened progressively since the 70s, Trumpist oligarchy is the result. Or worse.

You lecture us like we didn't grow up playing Monopoly and observing that the rich get richer and the poor get poorer until only one landowner is left and everyone owes them rent.