Good discussion. I'll offer my perspective. I believe that for all the people mentioned in this conversation (Brady, Diggs, Allen, etc.), there are three things they all have/do that sets them apart:
1 - Natural, God-given athletic talent: This takes different forms, speed, strength, gifted movement ability, and so on. But they seek to get the most out of what they have. (I do too, but I am not starting in the same place they are.)
2 - They are smart and teachable: That is, they are always studying and working to improve their craft. They work hard at getting better, whether that be their mechanics, their knowledge of the game, nuanced skill development, or whatever it takes. They receive good information (Coaching) and seek to improve (master it) where they can. They are "smart" from an athletic sense; that is, they can receive, process, and implement improvement knowledge far better than the average person.
3 - Competitive Passion: They are never satisfied, they always want more, they want to get better, they are driven and will never be outworked. It's the Grit, Drive, Passion, Obsession, etc., to work hard and be better than their competition.
There maybe better labels or descriptions -- and I do realize it is simplistic to say it is just these three things (for example, they also were born into environments that afford them the opportunity to take advantage of these three qualities). But I believe the combination above it what sets the great ones apart. Yes, others have these -- to some degree, all professional athletes do -- but they have these above and beyond their peers.
I am grateful our QB is a part of this conversation. I think of all the years we have endured without someone we can discuss in this type of conversation.