Inter Milan played quite well last season. Their attacking players were able to perform their duties properly. The team managed to score a lot of goals. This is why Inter Milan qualified for the Champions League final. However, Inter Milan's weakness in the last season was their defence. The team did not get the expected performance from the defenders. And so if Inter Milan's goal is to win the title next season, they will definitely need to strengthen their defense. If the performance of the defenders does not improve, the chances of Inter Milan winning the title next season are slim.
Inter Milan defensive lines indeed was quite bad because last season they were conceded 42 goals and this record is worse than the achievements of the 2021 season that at that time Inter conceded only 32 goals and Inzaghi have already concern about this and that's why he will bought more players for defender position
However regarding pre season match Inter have already win with big scores against Serie C team Pergolettese FC yesterday that they won 10-0 and Lautaro Martinez was scores 4 goals from this match and i know this is not the indicator of Inter strength because their opponent is too weak and easy to be defeated but Inzaghi has been confirmed he was satisfied with all of Inter players performance because their fitness levels have almost reached the target he wants
I also see the same thing as what you saw about Inter Milan last season, yes it was a fragile defense that they often got into trouble and had an impact on their results. I'm sure they will be very aware of that and prepare to improve their defensive line for the next season. Even in terms of goal deficit, they are better than last season's runners up, Lazio. But Lazio have a better defensive line than INter Milan, so that helps them a lot to stay in second place until the end of the season. I won't try to compare them to Napoli, because we know they were so solid last season.