The problem is that Bell wasn't worth his contract at any point, regardless of usage. He's been one of the least efficient players in football, on a per touch base, for years. Yards After Contact and Broken Tackles were both lower than Connor.
Bell is only excellent when he has a good OL or is force-fed the ball in space. 5 years ago, he was unique like that. Now, there are probably 15 players in the league who can be as productive and more explosive with the same type of touches (look at SF). Bell is a good chain mover, but that's it, and he needs specific usage to do that.