There is indeed quite a gap between the performance of the two teams that will compete this week and I think apart from being favored as hosts, Juventus also has the opportunity to win this match. Napoli still don't look very convincing after their heavy defeat to Inter and that will make it difficult for them to recover against a similar team.
I also think like that for the Juventus vs Napoli match because apart from Juventus still being quite strong so far, Juventus also doesn't want to embarrass itself in front of its supporters. Because Juventus is still aiming for the top position all this time, so whoever their opponent is, it will be difficult for them to win when they face them. Apart from that, as you said, Napoli themselves are still not very consistent with their performance so there is a greater possibility for Juventus to win at home in tomorrow's match.