It is increasingly difficult to me to accept any form of Venice Italy in the discussion of seasteading, just because it is built on swampland.
Venice grew because it’s banking laws and practices allowed currency manipulation more liberally than the rest of the civilised world at the time. And like compound interest, the effects of a business growing there meant the business could open offices in other countries and become an international player in finance and politics. All that has nothing to do with it’s location in an Italian swamp, or it’s gondolas, or that what they initially financed was boats. Today in the usa, each state can set banking laws favorable to banking, and some have allowed some pretty bad laws to get banks to grow there, and take a lot of money from the customers. I would not want to model where i live on South Dakota or Nevada just because they have prosperous banks there which make money on questionable practices of high interest rates, penalties, fees on everything, and hair-trigger foreclosures. But that is what made Venice rich.
And the banks failed when they became greedy, and backed the wrong interests, and people could not repay loans. Not because the city of Venice moved away from the swamps. The money flowing thru Venice had very little to do with waterfront property, only that when the first banks became international, they had their foot on the international financing of international movement of goods and money, and a ship held more (and cost far more) than an oxcart. Anything that cost more meant the bank took out more of the profit, raising prices higher for the consumer.
Venice rose and fell in financial and political power on the rise and fall of who could repay loans, and which politician owed favors to the banks, and who won and lost wars. The simple gloss-over of it being waterfront so that everyone living there made lots of money because they used boats is overly simplistic.
Consider any town along any river, someone there has a lot of something heavy they need to move 200 miles upstream, and the year is 1700. There’s no maintained roads, no railroad, no planes. And any profit made by selling the heavy thing is going to be taken by fees charged by the riverboat company. The fees won’t be made by the origin or destination towns, or people would just leave. But someone shipping downstream to the same location will have lower shipping fees. Someone closer may get the heavy thing to the destination more cheaply by horse and wagon, unless it’s managed by FedEx or UPS, of course. The few rich families of old Venice made money by financing the shipping companies that controlled delivery between source and customer demand. Nothing to do with Venice, as soon as they were international, they made money everywhere.
Im my opinion, Venice is not the model of seasteading most people strive for.