You really have to have contain in mind, especially against teams that are already limiting numbers in the box. 5 or 6 man box with a back releasing often spells a big play if the QB breaks contain.
Another thing that has changed is how fast the ball gets out of a QB’s hands. We are no longer talking 7 step drops out of max protect.
Neither of these things makes an outside pass rush irrelevant, but both are heavily aided by inside pressure. It’s the shortest path, and collapsing the pocket limits the QBs escape possibility. If you got someone that can force that center back, QBs get very nervous. That forces a guard to help, and then the defense has options.
The big problem last year was when those other things went well, we didn’t have an OLB that could beat a tackle.