Couple of things. Careful of confirmation bias here.

Saints defense may be related to coaching, or it may be related to finally "hitting" on high end talent on that side of the ball. Cam Jordan, Lattimore, Vonn Bell, Apple (has played closer to his draft status since coming over) and a smattering of others have turned into the playmakers they were drafted to be. Might be coaching or might just be playing 3/4 of Ohio State's secondary and these guys all work well together?

The running the ball thing. It comes back to the lack of play action in the Steelers offense more than balance. Rams, Chiefs, and Eagles need to consistently at least attempt to run because their passing attack is based on RPO's and play-action. So the rushing attempts are "baked in" and come regardless. The Patriots ran the ball because the Chargers forgot to pack their big-boy pants and got blown of the line of scrimmage from the jump. A great deal of some of the rushing attempts also came because one team was beating the snot out of the other.

When the Steelers were not trailing or only up one score, their offense was far more balanced. But once Conner got injured and/or they were coughing up leads or getting in dogfights with crappy teams, balance went out the window. With the offensive personnell the Steelers have, I would pass the ball to get a lead and run to preserve it as well.

The funny thing is that much of the conversation we have as fans about running and rushing attempts is purely results oriented. When the main RB has a ton of attempts/touches, people worry about too much of a good thing. Then the team loses a game or 7 with low rushing totals and people worry about not enough.

Stop turning the ball over on offense and start getting the ball on defense and no one will talk about rushing attempts.