1. There is no evidence to suggest there will be pop ins.
2.You do not know if people will or will not notice resolution differences as games will lower resolutions typically look softer in general and less crisp and DF will point this out.
3. Notice how you conveniantly left out framerates. I'm not talking only 1st party. I'm talking multiplats as well.
4. The rest you said is another topic entirely
Oh, the differences in resolution are so minimal to spot nowadays. The reconstruction technology is so good, even DF will get problems to find any differences.
Regarding the frame rates: Not all games have stable FPS and nevertheless are among the most successful games e.g. Fallout 4.