You are revising history with Darnold. He showed promise his rookie year. Detroit, Colts, Denver, Bills, Texans, Packers. All great games he put together his rookie year throwing to literal nobodies. Plus he ended strong.
His second year he improved significantly in every statistical category despite mono. Comp % TDs-INts yards, wins, etc. a good second year and the progression you want to see. Do you remember how abysmal this team was that year with him out of the lineup?
Third year he sucked and we dumped him. We literally got rid of Darnold as soon as humanly possible. Probably too soon, though it ended up being the right move.