I get a lot of noise in dark areas with all kind of sensors, lenses, apertures, focal length, exposure durations, crop factors.
Proof your point or I call BS.
At the moment you carry a load of BS.
First call: You are trying to tell there is a difference if a pic is cropped in post or if the area is cropped during aquisition. Total BS.
EDIT: Maybe it is beyond your comprehension how a sensor works: Imaging yourself as a photosite. And you are looking into the sky. And around you are several millions other people. Now tell all the people more than 500 meters away from you to close their eyes. Does your vision gets darker? Nope. Because it doesn't affect your eyes if other people far away from you have their eyes open or not.
If you believe otherwise: Give proof or I call it BS again.