i don’t understand why they can’t reuse the water.
Water cooled PC’s don’t need a constant supply of fresh water..
Cooling towers evaporate water to cool the hot side of the large centrifugal HVAC water chillers used on large cooling systems. You cool water to within a few degrees of the wet bulb temperature, warm it up 10 or 15 degrees F in the condenser tube bundle of that centrifugal chiller, run it through the cooling tower again, a continuous process.
Some of the water evaporates to give you a cooling effect on the rest, and some must be sent to drain to keep the mineral content reasonably low.
Is it a fair amount of water? Yes.
Is it the gobs of water people are freaking out over? Probably not, unless you’re in an area with a water shortage already.