It's just the opposite of https://en.wikipedia.org/wiki/Commodification - that simple.
This seems ideal for important necessities like water, housing, food etc.
Water isn't like that, and there is no way to make it.
It's about money. If you have a lot you can hoard commodities. If you have little you'll die of thirst, hunger, exposure...
> This seems ideal for important necessities like water, housing, food etc.
On the contrary, such commodities are regulated almost everywhere in the world to limit hoarding and speculation.