I actually think it's in Sanders best interest to sit, for now. There's no question he has a lot to learn and work on, and tossing him to the wolves would likely be as bad of result as all the other "failed" QB's in recent years have run into. At some point he's going to need to get snaps on the field. And maybe he can get some of that, if only in garbage time, as the season goes on. But his best chance, I think, is to just learn as much as he can right now, absorb as much as he can. Maybe if he (and Dillon?) play well enough this year, with two first round draft picks next season the Browns can draft for the OL and offensive playmakers and help set him up for potential success there.
Even at 1-3 the Browns aren't out of it in that division. The Steelers are overachieving at 3-1. Burrow is likely out for the season for the Bengals, who are a mess. And Baltimore's defense is the worst in the NFL right now (granted, tough schedule, but they looked bad against Detroit, and worse against KC) as they sit at 1-3. If you look at the Browns schedule, they have a handful of potentially winnable games coming up in a few weeks: Miami, NE, Jets, Raiders, Titans, Bears. And they close out the season at Cincy. It's maybe possible that Gabriel or Shedeur come out of the season looking like a player the team might be able to build upon under a cheap rookie contract.