Serious question, not meant cynically:
For you guys that use any of the specialized, and expensive, 'weapons' lube products, what do they provide that is not included in Mobil1 or other good quality motor oils? Same q for greases.
You want an answer based on reality?
"We don't know."
We don't know because what's ACTUALLY in a given product, and in what amounts, as these are usually trade secrets.
Therefore we cannot easily answer this question.
In the case of motor oils and transmission fluids, we at least know there are actual engineering standards which must be met in order to have earned the "SAE" on their labels. These are based on actual engineering requirements, born of much research in the automobile industry out of necessity.
The gun oil industry, however, has none of this in comparison. Most certainly not to the extent the automobile oil industry does, anyway.
For example, an oil coating does a good job of inhibiting corrosion, because it prevents moisture and oxygen from coming into prolonged contact with the metals. However, this can be enhanced by the addition of corrosion inhibitors as well.
What makes these differences in performance requirements important is critical to their application. For example, one absolutely critical function of the oil in your vehicle is its ability to maintain solids and contaminates in solution. Why? Because solids and contaminates in solution travel with the oil through the oil filter where they are removed. If they cannot be maintained in solution in the oil, then they deposit somewhere in the engine and build up.
So all those additives in engine oil are very much important in providing lubrication, corrosion resistance, contaminate removal, cooling, etc. They are proprietary, because doing a good job is an important marketing tool and must be kept secret from competitors.
But which ones? How much? Under what conditions are they designed to work best?
What works best inside an internal combustion engine may not work as well on cooler gun metals which are not operating in the same chemical and temperature environment of an IC engine.
In general, it's a good assumption that the less stringent requirements of your firearm are going to be more than adequately met by the oils/lubricants commonly used in your vehicle. So long, that is, as you apply common sense. Axle grease may not be your best choice to coat your guns and magazines, for example!
Just don't expect, or ascribe, magical unicorn abilities to it.