Although Inter Milan has won 3 UCL trophies, it happened a long time ago, where the last time they won the Champions League title was in the 2009/10 season, and that was a long time ago, it has been 15 years since Inter Milan has won the Champions League title. In the 2022/23 season, Inter Milan again advanced to the Champions League final, but their hopes of winning the UCL trophy were thwarted by Manchester City with a narrow score of 1-0. and now under the same coach "Simone Inzaghi" Inter Milan is back in the 2024/25 Champions League final.
So even though Inter Milan has won the UCL Trophy several times, because it happened a long time ago, maybe the mentality of the Inter players to win the title has faded a little, and Inzaghi is trying to revive that spirit.
After reading some of your replies, it seems you really want PSG to win the UCL title.

Although PSG is in top form, beating the more experienced Inter team seems impossible. Experienced teams always find a way to beat their opponents. Last season, for example, Dortmund looked eager and ambitious to beat Madrid. However, Dortmund lost their spirit after Madrid mounted a more consistent attack, and Dortmund ended up losing. The same could happen in the PSG vs. Inter Milan match.