These studies never take into account that the game is still ongoing while the ball is not in play. A lot of the game takes place before the snap, as does the strategy. The offense after a big play sometimes struggles to get to the line of scrimmage in time to snap the ball again.
There is a flow and rhythm to the game for those of us who enjoy the sport. Though I can understand where you are coming from.
Another interesting thing: one major advantage of speed is actually slowing the game down.
E.g., if you move quickly between plays, you can catch the other team with too many men on the field during a substitution. in that case, you sometimes get a "free throw" (if the play works out, you decline the "too many players on field" penalty; but if the play doesn't work out or the other team intercepts the ball, you take the penalty and pretend like the failed play didn't even happen.
So you can actually increase the length of the game by moving quickly in-between plays...
There is a flow and rhythm to the game for those of us who enjoy the sport. Though I can understand where you are coming from.