I expect the defense to take another step back after losing Kyle Fuller and not really adding anybody of significance in the off-season to make me feel any better about their lack of ability to rush the passer and create turnovers.
The offense still lacks explosive playmakers. Nobody besides Darnell Mooney scares you as a defense, and they don't have enough team speed at the skill positions.
Lastly, the opponents they are set up to face is going to be brutal. Aside from their usual 2 games against GB, they get the AFC North and NFC West this year, and also have to play Tom Brady again..
All things considered, this team isn't setup to be a playoff contender unless Justin Fields starts week 1 and plays above expectations. Great quarterbacks can offset a lot of things, but I don't think it's wise to assume that's going to happen right away.