Actually, I personally didn't expect Napoli to experience a decline in performance like now. The reason is, last season Napoli won Serie A. It shouldn't be difficult for Napoli to compete in the top 4 of Serie A this season, but Napoli is only able to compete in the top 10.
Inter can maintain their consistency if they succeed in retaining their team and coach. that's what actually happened to Napoli. there are players and of course changing the coach's chair has a big impact on a team's game. because they have to adapt to the playing patterns and strategies of the new coach.
if Inter can maintain everything next season, that would be great and it would be difficult for other teams to compete with Inter. but it's still not an easy thing, because other teams are aware of what needs to be improved this season so they are left behind by Inter who dominates the standings.
I just hope that the competition in Serie A will heat up again. Honestly, I don't really like leagues that are only dominated by one or two teams.