This has been an ongoing problem for the Steelers
We saw this problem begin to develop in the early 2010s. A lot of the elite defenders that called Pittsburgh home retired, and the team had to rebuild itself. It did that quite well on paper, establishing an elite offense headlined by the infamous “Killer Bs” that kept this team at the top of the AFC North.
That period, while fruitful on paper, yielded very little for this team. The occasional playoff run was always ended painfully, and despite the team having the best receiver, running back, and offensive line (to go along with a future Hall of Fame quarterback), this franchise has nothing to show for it.
And then that period began to decline. Ben Roethlisberger continued to age, Antonio Brown and Le’Veon Bell had their respective derailments, and the line retired. This team was still competitive but was falling off. Big changes needed to be made in order to adapt to the new NFL, but this team remained consistent.
Consistency can become an issue though, when it doesn't lead to any major success. The Steelers haven't been to a Super Bowl in nearly 15 years, and they haven't won a playoff game in almost 8 years. Instead, it has been consistently average to above average teams that do just enough to win but not enough to thrive.