Josh Allen had horrible support his first year. The Bills had the 32nd highest paid Oline in the league, and most of the starters are now out of the league. They had the 30th highest paid WR corps (not last because of Kelvin Benjamin). They had an average paid TE corps, but only because of the ghost of Charles Clay. He had Nathan Peterman and AJ McCarron to learn the position from.
Despite that he still had some electric moments every game and got visibly better over the course of the season.
If anything, JA's first year is a signal that you can take a top-level talent, and even if they're raw and in a horrible situation they will show flashes of greatness.