Although the three yards and a cloud of dust is a swell approach, it should not be the only scheme as that would make the offense one-dimensional. With that, an OC worth it’s salt will also use the fly, go, and wheel routes, trips to the right or left, the Hail Mary (which is the greatest football play there is) as well as other long bombs, and spread offense.
The game, much like life, is ever changing and evolving. Keep up or turn on ESPN Classic.