Just because something seems like should work doesn't mean it will. Air conditioners are simple and cheap to install. An insulated swimming pool in the basement is not.
Or in other words: 11kW-hrs of cooling, comparable to an entire Tesla Powerwall.
We aren't talking about entire swimming pools here. Just a few cubic meters of water. Shift the temperature delta as you see fit but... It's actually very space efficient.
I know that IceBear left the water around 45F, so take that for what you will.
Either way, we aren't talking about entire swimming pools here. Just a small, single digit number of cubic meters of water.
Today. In my chats with the sort of home improvement types that seem to be in this thread, we're less concerned with today and more concerned with the cost of things in the future, as societies include "climate taxes" (in the form of actual taxes, subsidies, or whatever else) in the cost of things.