Very true. The modern day QB still has to have more mobility than Kaaya ever had. He could have made it pretty well in a full on air raid under Leach or Jay Norvell or something. None of these modified systems meshing air raid with other concepts like what Riley, Briles, Dykes, etc are doing. Too reliant on QB mobility.
Pass first QBs are still the most lethal.. but you've got to have some kind of ability to keep it and move the pocket. Just like Matt Corral, TVD, Kyler Murray, etc etc.
The only one i can think that still defies that logic is Tom Brady. Manning could too but he was even a better runner than Kaaya when the defense gave it to him.