Strong disagree. All of the elite QBs have superb intangibles (Confidence, smarts, gamer, leadership). Obviously, you need to have the physical attributes, athleticism and arm mechanics, but if you lack the “mental makeup” you will not be an elite QB.
I also disagree with your point about QBs getting drafted into dysfunctional organization which results in them not playing well. I believe if you’re good enough QB it doesn’t matter which team you’re on, you will excel. Imagine if Mahomes was on the Jets. Would the Jets stink as they do now? Absolutely not. They would be a playoff team. Great QBs make others around them better. He would make the WRs look a lot better than they actually are, running game would then be better and in general the team would have more confidence.