@BigMacAttack8u
That is actually kinda true, even in semi-high elo and definitely pubs. I guess our eyes and brains work like the T-rex in Jurassic park, i.e searching for movement/change in the landscape when we are scanning the FOV for enemies and therefore easily can miss totally stationary enemies. But that wont happen very much against high elo players. What many mid elo players, like hardstuck plats and below, think is 100% wall hack are more often than not just high elo players who are incredibly smart.
Those top players have so much experience, skill and game knowledge that they will almost unconsciously use what he cant see or hear to determine exactly where the enemies are, based on the method of exclusion. For instance, if they hear your footstep from a certain direction, they will immediately know how far away you are. And since they know every possible way and place you can be positioned on the map, they will also know where its possible for that enemy to be. And if they dont see you "there", "there" or "there", they will know that the only possible place you can be is "there", even without even having a second of line of sight of you.
But then there are the occasional wall hackers ofc 😉