They’ve mad changes that have made cover 2 more effective. Teams have smaller and more agile lbs that can help in coverage and they’ve added an extra db on the field too. Which is why running is more effective now b/c there’s no big bruiser run stuffers anymore. RBs just gotta get past the first line of defense.
Yeah they've made modifications to it and you can even say the cover 4 or two safety shells have been a thing for years.
I really don't know why everyone is making a big deal of it.
There's also the fact some of these QB's are learning new systems as well with new coaches, coordinators, etc.
Midseason these defenses are going to get lit up. We just had a rookie almost put up 400 yards with one of the league's worst OL's, Kyler Murray had a 158.3 last week, etc.