I still think Inter Milan is the strongest team in Serie A this season. However, Inter Milan's overall performance has been a bit erratic and weak. If Inter Milan could have maintained their performance in the last few matches, Inter Milan would have been at the top of the table now. Inter Milan has lost points in two of the last three matches.
However Inter molan still has a chance to grab the top spot in the table. Inter milan is not far behind Napoli. Inter Milan is only 1 point behind. If Inter Milan can continue their winning streak, they will be able to grab the top spot in the table very soon.
Inter has got weak at some point at the other they got better with their performance so this inconsistency Literally made some people lost faith in them such that probably they don't trust them enough to be able to really maintain the wins they have gotten at some point, even Napoli has got almost similar pattern on their performance but having Inter win them was a good one and like you mentioned, moat likely Inter has got a chance at the trophy this season. A point difference isn't much for Inter to make up for.
The championship fight between Napoli, Inter and Atalanta is still ongoing. There is a one point difference between Napoli and Inter and Inter is a little bit far from their old performance. While everyone expected a better performance from them, we can say that they were overshadowed by Napoli this year. When they experienced unexpected points losses, Inter naturally ranks second behind Napoli. If we think that this race will continue until the end of the year, I think Inter's chance at the championship will continue until the last weeks.