Aim assit can be turned off. It would be interesting to see how well these control pad players do with no aim assist. Granted they still have amazing control of the pad, very skillful and must take years of practice
There are numerous videos of the pro's trolling each other by turning off aim assist
The difference is massive and they suddenly look far more average. Still good, but not god like
The biggest thing with Call of Duty pros, not just Warzone pros, is they KNOW how to use aim assist to its maximum effectiveness
For example, if you strafe whilst ADS aim assist is stronger than if you stand still. Etc etc