You are completely wrong. I know that's what your intuition feels like from watching games, but if you actually get a stopwatch out and clock it, you'll see it's much closer to op than what you posted. Very close in fact.
If you don't believe it, find a actual game and time it. I did this on a game.
For example from the 8min mark to the 2min warning (6 mins of clock time) there were only 2m15s of action. Only 37.5% of the clock time was action. And that was an extremely conservative time. It was the 4th quarter, had multiple scoring plays, and multiple timeouts - essentially everything possible to do to stop the clock and still it maxed out at < 38% of the clock was actual game time. If you instead do this for a full game (not the end of the 4th quarter), and especially games that aren't close and you'll see it's way less. Definitely not what you're expecting.
Football is a tiny amount of "action time" as compared to "clock time".