It's not that simple, actually and I thought I made that point when I referenced humidity alongside temperature since the dew point is a relative relationship between these two things which is when condensation occurs.

"Free cooling" is not a new concept, but it's known to be costly and only effective in very specific environments and circumstances which does rely on exposure to the elements since it requires air from the outside to be mixed internally and humidified (or dehumidified) which often offsets any gains you make while requiring extra labour from performing maintenance on the air filters and such. Most data centres do not use the outside environment, they build a facility with a large enough air capacity to dissipate the heat of whatever they're cooling as a closed system.

Even when it is a viable option the industry isn't keen to adopt it because it introduces complexity and variables into an industry that demands 99% uptime minimum as an industry standard. My point stands that it's an idea trying to piggy back its idea onto another one, even if free cooling was viable.