

I think you have to look at the actual orders of magnitude difference in raising the temperature of water versus air. The Arizona story you linked is about a study that found up to +4°F (+2.2°C) temperatures in air.
The same amount of heat, spread across the same volume of water moving at the same speeds, would only raise that water by 1/830 as much, for a +0.0048°F (+0.0027°C) 1/3300 as much, for a +0.0012°F/+0.00067°C temperature change across the same area/volume.
(I got to 830 by taking the specific heat of dry air of approx 1 J/g K at room temperature and regular atmospheric pressure and 1.22 kg/m^3, versus water’s 4.184 J/g K and 1000 kg/m^3).
(Edit: I fucked my math. Water has approximately 3300 times the heat capacity as air, per unit volume, and I just looked it up directly).
The higher conductivity of water might be offset by the higher convection potential of air (because air responds to temperature changes with differences in density/pressure, which creates wind in itself), so that the heat will spread through either medium relatively quickly and therefore dissipate very quickly with distance to the source.
I just don’t see a world where a data center raises the water by even 1°C, even locally.
What currency are you using for this comparison? Definitely not USD.
A Tesla Model 3 runs for about $40k. A Camry runs for about $35k. Or if we want to go down market a Nissan Leaf is about $30k and probably comparable to a $25k Sentra.
Similar trim levels of vehicles offered as both EV and gasoline powered show minimal difference. Compare the Ford F-150 Lariat in both the gasoline ($75k) and the EV versions ($79k). Or the new Lexus ES, where the EV ($49k) is actually cheaper than the hybrid ($51k).
And if you go into the used market, EVs are starting to hit that market in real numbers, too. Plenty of options for under $20,000, and a handful of options for under $10,000.
Cars are expensive. EVs generally are close to that already expensive price.