Sidestick concerns
The lack of visual cues or "feel" of the other pilot's control position is a bogey man.
You see what the jet is doing and question the other dude/gal and then get in the loop.
I have soloed dozens of troops in the Viper with the sidestick and zero feedback and zero stick movement ( actually about 1/8 inch after first few came on line). That's the family model. In the SLUF we had no two-seat trainers so first flight was solo. Flew close chase and talked to the troop.
As several here have stated over and over, it's the instrument crosscheck and determining if the jet is doing what it is being commanded to do, or not.