1. That time in between snaps is the setting of the chessboard for each and every play. In between the plays is often where the most cerebral work in the game comes.
For one thing, the inevitable result is that football has become an overly scripted performance more than a real sport. And your post doesn't address my original point on this: Why the hell does the clock run while all this "cerebral work" and "setting of the chessboard" is going on?
2. The size and speed of the athletes in every sport has increased over the years. Hockey and basketball are good examples as well.
Players getting bigger and faster is one thing. How about when many of the positions are played by men who are bigger and slower? Is there any other sport out there where this guy would be considered an "athlete?" LOL.
3. All players in every sport are more specialized than they ever were before. It is fun to see a defensive lineman lining in the backfield up to block for a running back near the goal line, but why is that even important as a flaw?
Specialization itself isn't a problem, but football is the one sport where specialization is tied to variations in physical size -- which means players who specialize in one thing are completely unsuited (by physical nature, not talent) to others. You don't see this degree of specialization in any other sport.
And the teamwork point you make really underestimates the role of entire teams even in cases where one player can dominate on the scoreboard. I don't know any pitcher who tossed a no-hitter and struck out every batter, for example.