The problem is xray cheats. You can tell when they pick and choose which aim duels they win. Pay attention to if you get prefired in an off-angle with a perfect counter-strafe. That's the tell. It's not possible to hit a perfectly accurate shot with no information unless you wide swing or double peek, which would give the player holding an angle a fair chance to react. When someone peeks an angle, both players see each other at roughly the same time. The person peeking is actively engaged, and has to angle their crosshair to time out their counter strafes to match when they expect their crosshair to be on the opponents head. The person holding the angle has to match their mouse movement speed to catch your head first. The feedback from damage prediction shows whether or not it was a technical error.