~Snip
I think this might be issues from the board itself, even past manager like Allegri couldn't turn things around for them, who did pretty well before.
I think one reason for their drop is the quality of players they have and the fact that other teams in the Serie A are growing improving their squad makes it more difficult for them to dominate like before when they were having more reputable names as club players. We saw Napoli fighting hard to keep Conte and one of the negotiations the board are giving him aside high pay is the fact that they are going to fund him in order to get top players to the club.
Retaining Conte as coach will basically not guarantee that Napoli will be able to maintain the same performance as this season. Players' performance can easily change and injuries to some key players can change the overall performance of the team. I don't think Napoli will be able to defend their title this season, the same story as last season could repeat itself.
Yea this is still possible but they can't just sit down and wait for someone to come collect it, they have to fight, strengthen the squad in order to compete better even in the UEFA Champions League.
If they believe on Conte it's not because he has proven himself in the league at various club already. What differentiate a top team from a mid team is that they thrive to continue their top performance. Even if some players might fall off, there are still others ready to step up and seize the moment.