Napoli are not in the best shape now, and it does not look like they are changing for the better, they continue to lose points in every match with any opponents. Inter came to the end of the season much better prepared, I doubt they will allow anyone to displace them, in fact, Napoli are closest to them and if they do not start winning, Inter will increase the difference, and Napoli will have to play Milan and Bologna in the next matches, so they can lose points again.
I personally don't think Napoli will win the Serie A title this season. Napoli were in very good form at the beginning of the season. But Napoli are in a very bad position at the moment. Especially in the last 7 matches we have seen Napoli's poor performance. Out of the 7 matches, Napoli only won against Fiorentina. Napoli drew in 5 matches. That is why Napoli lost the top spot in the table.
Napoli is 3 points behind Inter Milan. This is not a big gap. However, since Napoli's performance is very poor at the moment, this gap is likely to increase in the future. I think Inter Milan and Atalanta will continue to fight for the title until the end.