the more expensive it gets, the less people can afford it

You know, all these arguments avoid answering the question about how much more expensive water could be. And I suspect the general answer is: not much. Mass producing fresh water is well understood process. It’s also a potential source of sodium for sodium-ion batteries, cheaper alternative to lithium-ion.

And then there’s the fact that desalination is a huge environmental disaster.

I’m fully aware of that - what’s missing there is proper regulation by local governments, preventing excess salinity of water dumped back to the ocean