[washadjeffmad]

Because humans perceive temperature in terms of radiant heat, perceptual comfort is different from gauge temperature.

I'm not sure how, but our smart thermostat intuits this to adjust to our comfort, not just a temperature.

Because of our climate, it's also convenient to program our fans to run at certain intervals, control for a set point for humidity, or to base behaviors off of other sensors (air quality, etc). Conditioning air isn't just for maintaining a temperature, and most traditional thermostats, while not ineffective, are completely unable to account for these things.