Oil platforms are a technology for floating permanently on the high seas, and cruise ships are a technology for self-governance on the high seas, and if you combine these two technologies, imagine cruise ships that never dock but float permanently. Imagine if they were 10 times as big. Imagine if they were modular and could move about and you could choose the neighbours you wanted to live with.
Nearly half the earth's surface is unclaimed by any country, so seasteads would be startup countries on the blue frontier. Patri Friedman is a Google engineer and theorist of political economy who realized that if society floated, it would completely change the nature of governance itself. If seasteads are modular and can be moved about, allowing people to choose new societies, we'd create a market of governance providers, competing to attract residents.
Regulatory fiat cannot create a market at a technologically interdependent interface. And by the same token, regulation and so-called monopoly power rarely prevail at modular interfaces between stages of value-added technology.