The offense really didn't go anywhere. It basically stayed the same by the numbers.
2018: 2143 yards rushing w/ 24 TDs, 3615 yards receiving w/ 28 TDs
2019: 2064 yards rushing w/ 24 TDs, 3554 yards receiving w/ 29 TDs
As for Sam having a disappointing season, not really?
2018 Sam: 3292 yards, 64.7% completion rate, 25 TDs, 5 INTs <-- On a team that actually played some sort of defense, wasn't completely wrecked by injuries
2019 Sam: 3462 yards, 65.1% completion rate, 29 TDs, 9 INTs <-- On a team that couldn't stop tripping over their own dicks, played much better competition, forgot how to tackle, who had like 500 guys in the medbay
You're absolutely right that Sam ain't the problem. Kid has killed himself for us. Unfortunately, he's stuck with an egotistical idiot for a HC who has surrounded himself with even worse coordinators. When your coach's stupid play calling constantly get you into 3rd and long it's hard to have a lot of success. When the defense is so bad you constantly have to play from behind and under pressure it's hard to have a lot of success. Yet Sam still managed to essentially match his Sophomore campaign.
What we needed to see this year was better play calling and game decisions from Mensa and Orlan_o actually figuring out how to coach his side of the ball. We got none of that. Instead, we got a fuck ton of injuries and better opponents who took full advantage of our inept coaching staff and roster deficiencies.