I overall agree with your points but I will say that the type of person who probably excels at a life-or-death job like swat is someone who lives for that adrenaline rush in the first place. The problem is in their over-activation, like an overly-active immune system.
I watched the Uvalde PBS Frontline documentary and what stood out to me is that all those cops were glorified ticket cops one-step removed from mall cops. The only two guys showcased to seem to know what they were doing and had a willingness to do so were the border patrol’s equivalent to swat, BORTAC, who seemed professional and were the ones who entered the room first and ultimately eliminated the shooter.