Napoli performance last season was impressive but when Spalletti left and another key Napoli players also left, Napoli performance became unstable this season. Rudi had bad luck working with Napoli, because indeed his task was not easy. Even, many fans not happy on some of his decisions, for example in the match against Fiorentina when he replaced Osimhen with Giovanni Simeone.
I think Spalletti is the only one who has had such an influence on Napoli game and his departure makes Napoli's situation this season not very good in terms of their performance. There were no influential players in the Napoli team who left last season. Maybe if I'm not mistaken, Kim was the only one who chose to join Bayern Munich. Napoli can say that their squad is still dominated by the players who played last season, it's just that the change of coach is making them difficult this season where Rudi Garcia tactics are difficult for Napoli players to understand.
If Napoli wants to fire Rudi Garcia, I think it will likely be a blunder for them because we often see teams that frequently change coaches and certainly won't be able to make many changes in the near future. However, that is up to the Napoli owner because if he is not satisfied with Rudi Garcia performance, he could fire Rudi Garcia if Napoli loses again in the next match.