Posters have hit on many points that I share, but just wanted to list the three things I see as the main reasons for the team's struggles. Mainly for therapeutic reasons.
1 - WRs cannot get open. Are the coaches allowing the WR/TE to change their route depending on the coverage they read? There are some offenses that give the freedom for WRs to change their routes depending on their read of what the coverage is. This takes a lot of coordination on the WR and QB, but if done right, it beats coverages. It seems that the WRs have one route to run and that can severely limit the ability to change on the fly.
2 - Kap has very little pocket awareness. When Kap senses pressure, he always tucks and scrambles as opposed to a simple sidestep that would allow him to keep his eyes downfield. Instead, he will tuck and run outside the pocket, successfully evading pressure, but severely limiting his options once he's outside the pocket. His WRs already aren't that good, but now, once outside the pocket, he has cut down the field in half further limiting his options. There's always a spy now, so he never has a clear lane to scramble. There's got to be a hot read open somewhere, on every play, due to the assigned LB spy.
3 - Offensive playcalling has been atrocious. So many have hit on this, but I think the biggest blunder is getting away from traditional run sets. Running out of the pistol just doesn't give the RB a downhill start, which favors power blocking and tough inside the tackles running. With an 8 man box, I get that running between the tackles is harder, but I still feel that with the monsters along the Oline, that they can still consistently gain 4 yards. Then use play action off of that.
A big part of what made this offense effective is that it always outnumbered the opposition in plays ran. This would tire the opposing defense and allow for big run gains in the second half of the game. Simplify the run game by leaning heavily on the sheer physical dominance of the Oline.