Free markets are rarely naturally sustainable. Left to their own devices, they converge into monopolies; it's explained pretty simply with a bit of game theory and the advantages afforded by the network effect and economies of scale.

This is exactly why the US had historically adopted anti trust laws, the FTC, and the Competition Bureau. The public used to know what's up. Clearly many people haven't gotten the memo, and are all too happy to drink the ancap cool aid.