There is still hope to succeed in both competitions, with two games remaining, there is a possibility that Napoli can lose one of their games if only Inter will take their chance in the competition. Inter has good squad, their is rarely a second team player in Inter because all of them are more experienced, during the Champions League against Barcelona, when they started making substitutions, it was the players that came in who made the game as tough and won at the end without going to penalty shootout. If Napoli wants to win the title, they would rather not lose any points, if they both draw with the same points, Inter has more GD over Napoli, which will earn them the title.
Inter Milan is not worried about the Serie A title at the moment. And I would say they don't need to worry. It is not possible for Inter Milan to win the Serie A title if Napoli can win their last two matches. And the important thing is that Napoli's opponents are very weak. The possibility of Napoli dropping points in these two matches is very low. So I don't think Inter Milan will give full effort for Serie A. But Inter Milan will definitely want to win the last two matches.
Milan now has the Champions League title. Inter Milan has qualified for the final by defeating the hot favorite team like Barcelona. Undoubtedly, Inter Milan has the ability to be the champion. But PSG is not a weak opponent this season. Like the semi-finals, the final will also be very competitive.