I was a qb for our highschool team in Ok, largest school classification, state championship under my belt. My qb coach was a former byu qb. I learned alot about footwork, release, proper throwing techniques, from this dickhead. We ran the option, and still passed when we needed to.
I had alot of the qb technique mastered, could throw the ball hard and far, decent speed. Even at my best, I could only handle about half of what I see pro qb's have to handle/process. I could lead my team, but my shortcoming was proper reactions to the speed of the game.
Technique is only one tool. I've seen some hof pro qb's with terrible footwork, and some have all the technique/athletic talent in the world, top 1%, but they can't: process the game fast enough, or understand it well enough, or, they simply just may not be able to lead their offense. I see about half of the qb's in the nfl right now who fit that mold. They hold their team back, and will never lead them to a championship.
They've all been playing QB all their life, with the best coaching avail, and are all in dedication/committment wise to fullfill their dream of being a hof qb in the nfl. Yet 95% of em don't have it, for one reason or another, to be able to achieve elite status. The elite qb's, somehow someway, figure out a way to make it happen by leading their team and performing in the clutch.
Combine my playing experience with coaching football for 7 years, and I'll say that there's just some attributes that can't be taught or earned, you have to be born with it.
I don't really like him, but Brady is a great example. Looks like he's dragging an anchor when he runs, his technique is just ok imo, but when the games on the line, he comes thru and wins the championship. Cousins, Carr, Tua, Herbert, Purdy, etc, it's obvious they'll never get there.