I agree with you. We have seen great work from Spalletti last season. He was able to keep the players of the squad confident. This is why Napoli has been able to play consistently well and dominate Serie A. Spalletti was friendly with the players. He was able to spot the weaknesses within the squad easily. I don't think new coach Rudi Garcia can do that. Also, several key players in Napoli's squad have left the team. Overall I think we won't see the dominance of Napoli in Serie A next season.
I agree, most likely Napoli will not be able to repeat their success in Serie A. Spalletti was good in Napoli, but such an understanding between the coach and the players does not always arise, you remember the times when Spalletti was the coach of Roma. Then there were many conflicts between the coach and the players, and what is the conflict between Spalletti and Totti worth. In those days, Spalletti was perceived by me rather negatively. Sometimes it happens that all the components add up and an excellent result is obtained, which seems impossible to repeat again.
Rudi Garcia may not be able to be like the old Napoli coach but I'm sure that Rudi Garcia will provide new experiences and give the best for Napoli even though one day there is a conflict that is a common problem in football.
But what is certain is that we have to try to give Rudi Garcia confidence that everything will be fine and hope that success can be achieved again like when he was with Spalleti.