Yeah, like the others have said, defenses have adapted to a pass happy league. Very rarely do you see defenses run traditional base packages 3-4 & 4-3. Most NFL defenses run a 4-2-5 or 3-3-5 as their bases due to the speed and shotgun/pistol formations that Offenses run out of exclusively.
Not saying the NFL will ever go back to a heavy run dominate league like 1980’s and before, but OC’s would be smart to take advantage of smaller defenders and bully them forcing them to stop the run then go over the top like in the old days!