Inter is just too strong at the moment, far ahead of others. They're performing well both in the Champions League and in Serie A. The team is dominating everyone, and now Napoli has suffered heavy defeats at home. This year's Napoli and last year's Napoli are like two different stories, completely different approach. Napoli has been awful, and their poor home form continues. But, you can't really explain the scoreline; it's hard to believe it was 3-0.
On the other hand, it was a perfect game for Inter. However, they added an injured player. I hope the players can recover faster from their injuries.
Napoli results depends a lot from Osimhen and Kvaratskhelia performance. This season started with a lot of problems between Napoli and Osimhen, the players skills dropped comparing to the previous season and so Napoli are dropping in the ranking to the 5th spot for the moment. It is true Osimhen scored 6 goals in the ten matches he played but I think he could do better..
Yesterday's defeat by three goals was bad for Napoli, their defence took heavy damage and that's the other part of Napoli's problems. Next time they will face Juventus and two weeks after Roma. These two games are the most dangerous ones for Napoli and they have to win it in order to stay in the competition for a Champions League spot since the scudetto is getting away from them.
Walter Mazzarri failed to bring Napoli to secure points, even failed to secure 1 point. under his control, Napoli suffered 2 defeats and 1 win, a bad start even though I know the club they are facing is a top class opponent. for Inter, this victory confirms their position in the standings, and only Sassuolo has been able to beat them so far.
On the other hand, even though Osimhen and Kvaratskhelia scored more goals, that was only for them. What Napoli needed was 3 points at the end of the match. as you said, Napoli defense has been severely damaged, I agree with that. I think there is no hope left for Napoli to defend the Scudetto this season, they need a miracle to do it.
Who would have thought that slowly but surely Roma finally squeezed into the top four this week, Napoli failure brought a blessing for them to sit in the UCL zone, even though both clubs currently have the same points. It is very difficult to accept Napoli out of the top four, and their position in the UCL is also threatened by Braga.