That's just it. They were in jail in 2021 with the draft. Christ, the Raiders already cut an OL who was picked 16th, and no OL went after the Steelers until the 37th overall pick which was 17 after the Steelers took Harris. Teven Jenkins selected by the Bears also was considered to be cut.
I mean it would have likely made sense for the Steelers to move down to say the 30's and pick up an OL and an extra 3rd, but that is hindsight and there are no guarantees then. Also everyone points to Creed Humphrey, but he lasted until the 63rd pick.
Kendrick Green was just a bad pick. The Steelers couldn't have traded up because they lost alot of draft capital in trading up for Devin Bush then also trading for Minkah Fitzpatrick. One of those looks like a good move.