Stone Forsythe is earning his money
Stone Forsythe has had to do a ton already this year. He has already doubled the amount of career snaps he has had in his first two seasons in his third year. Last season, Forsythe played 128 snaps and was graded extremely poorly by Pro Football Reference (subscription required), but in 2023 and with more reps, Forsythe is grading much better, especially in run blocking.
Forsythe has also had to play left tackler and right tackle. In Week 7, he stepped in for the injured Abraham Lucas and also Jake Curhan. Curhan has played right tackle for the most part since Lucas was injured in Week 1. Curhan was OK the first couple of games but then he was pretty awful in Week 4. Lucas isn't yet ready to return so Seattle is still trying to find an answer at right tackle.
That might be Forsythe moving forward until Lucas can return. Forsythe is a massive human at 6'9" and 315 pounds. In 158 pass block snaps this year, he has allowed 2 sacks and 3 quarterback hits. That's definitely not bad for a starter, and especially not bad for a guy who is normally a backup. (Now whether Forsythe is really good against the Browns' Myles Garrett is another thing, but there's a chance he does pretty well based on how Forsythe has done this year.)
Still, Forsythe has graded better as a run blocker and the Seahawks must establish a decent run attack to win most of their games. Geno Smith is capable of being good, but he also needs run support to help him succeed, as opposed to someone like Patrick Mahomes who could win most games by throwing on every down. Seattle should be able to run to the right side with Forsythe leading the way fairly well and that should help the team win a bunch of games.