Deshaun Watson currently plays for an interim head coach, is supported by no real front office structure, and (due to injuries, suspensions, etc.) essentially has no supporting cast. Furthermore, Bill O'Brien booby-trapped the team's future drafts on his way out the door, and Jack Easterby is playing wannabe Lorenzo Di Medici with the coach/general manager search, so things won't get better for Watson for a while. That has left me brainstorming about whether any quarterbacks in history who were as good as Watson were ever trapped in a more hopeless situation.
Archie Manning leaps immediately to mind. Archie played for a string of terrible coaches for an organization on a shoestring budget throughout the 1970s.