Well, there is plenty of hydrogen in the water indeed. If there was any worry that we are going to run out of hydrogen, and willing to pay hundreds of dollars per kg (uranium fuel cost), we would totally get it from sea water.

In which case hydrogen supply would be technically infinite.

As for your second concern, could you elaborate, why centralisation such a critical barrier to achieving co2-free energy production? Never heard this argument before.

Big government, big industry, crony capitalism, corruption, political control of an essential resource, politics generally, secrecy, coverups, payoffs, concentration of power, etc. etc. which you would not get or to a much lesser extent (verging on negligible relative to nuclear) with some alternative energy sources like solar.

Solar and wind are fine for residential, which is 13% of global consumption.

Transportation and industry, with their 75% , would need some clean source of energy, for which calm nights are not a problem, crony capitalism or not.

Yes, you need some source of clean energy for which calm nights are not a problem.

If only batteries were getting really good... oh, they are. Batteries are not a source, but coupled with a source, your calm night problem is mostly taken care of. And batteries+renewable sources don't need to be 100% of the solution in order for them to effectively wipe out the value proposition of nuclear power in most situations. Yes, you can find exceptions, I'm sure.