He was well below average in opportunities, completion rate, yards per attempt, WAR, and ranked (or tied for) last in QBR Against and boom percentage.

Source: https://steelersdepot.com/2023/05/steelers-free-agents-lb-cole-holcomb-elandon-roberts-2022-coverage-data/

Howell fell well short of three of the current season leaders (Mahomes, Purdy, Herbert), had a comparable overall performance to Josh Allen as measured by total QBR, and did a lot better than Dak.

Source: https://www.bleedinggreennation.com/2023/11/29/23980901/eagles-news-lane-johnson-injury-49ers-game-nfl-right-tackle-offensive-line-philadelphia

Jackson (10th in QBR) was better than Burrow (11th) during the 2022 season.

Source: https://profootballtalk.nbcsports.com/2023/04/23/why-didnt-anyone-else-pursue-tyler-huntley/

That’s the difference between ranking 23rd in QBR over the past two seasons and finishing last, behind Davis Mills, Zach Wilson and Baker Mayfield.”

Source: https://nesn.com/2023/02/espn-pinpoints-key-move-patriots-should-make-nfl-offseason/

When Meyers was on the sideline, though, his QBR dropped to 30.7.

Source: https://nesn.com/2023/02/espn-pinpoints-key-move-patriots-should-make-nfl-offseason/