Number 2 has merit. Here are a few more.

1. Most thermostats do require calibration, and nobody has time for that. This has a similar effect to your second point. Proper air flow (or lack thereof) throughout the home is also important.

2. Sunlight makes a huge difference. A temperature that feels comfortable at night may not feel comfortable at noon in a home with a lot of natural light. Same as a sunny vs a cloudy day, indoors or outdoors.

3. Men and women have drastically different tolerances for comfortable room temperature. In general, non-menopausal women tend to appreciate a slightly warmer room than men. This plays out in office spaces all over the world, with many women running space heaters under their desks.

4. Clothing obviously makes a huge difference. Some people prefer to dress for their desired temperature; others prefer to dress for their physical comfort and let the HVAC balance things out accordingly.

5. Medical conditions and medications and diet can all drastically affect one's body heat output. For example, anything that boosts serotonin is likely to make one run hot. Stimulants will constrict blood vessels and make one cold, especially in the extremities. And we all know what alcohol does (dilates blood vessels, allowing more heat to escape the body, lowering one's body temperature despite actually making them feel warmer). Blood sugar levels make a difference. The list is endless.

But it's interesting that most of your thought process went into how HVAC systems and humidity work, versus the simple fact that the people themselves are just drastically different (see points 3 through 5).

This is removing moisture from the air, making it feel colder.

That’s not how humidity works. Higher humidity means that cooler temperatures feel much colder and warmer temperatures feel much warmer. Even the heat index calculation shows this. Just try it out for yourself, or look at the formula. https://www.weather.gov/epz/wxcalc_heatindex

People's AC units are not actually cooling anywhere near those temperatures. The unit is just on 100% of the time at those temperatures, and they could realistically increase the temperature a great deal and get the same results.

I don’t know why you think this. Maybe you only have a single stage AC or maybe you’ve never actually measured the temp with an extra thermometer, but you can get the ac 40-50°F cooler than outside, both by removing humidity (which decreases the “feels like” temp) but also through actually heat removal from the house. You might just have bad insulation as well.

If you live in a dry climate you can do the opposite. Pump humidity in using a swamp cooler, which places moisture in the air and then immediately causes it to evaporate carrying heat with it in the state change. You’re cooling the air slightly and since moisture exaggerates temperature changes it feels cooler to you.

My thermostat is right next to my garage door, which is not insulated. This is probably where the majority of heat enters the house. So the thermostat thinks it is warmer than it is.

I've got an Ecobee thermostat and they sell little temperature sensors that you can place anywhere in your house. You can configure which sensors are used at which time - for example I have a sensor in my bedroom, and configured it to only look at the bedroom temperature overnight. If you select multiple sensors, it averages them.

It's a decent solution to this problem.

Yeah, those are all good points and certainly factor in. There are objective studies about human comfort preferences used for building design. I expect OPs question is a roundabout way to ultimately ask about comfort preferences.