It will surely be season to forget for Inter Milan if they eventually lose out on the trophy to PSG, just as you said, they've lost trophies this season that were supposed to be at their disposal. The last resort for Inter Milan is this trophy and we're also aware that they started dropping points unnecessarily in the league when they got to the Quarter finals of the competition and it continued even after they eliminated Bayern Munich to face Barcelona. In fact before the first leg game against Barcelona, they lost three consecutive times, twice in the league and once in the Coppa Italia. So if they lose this, it's definitely going to be a big blow to them.
This is a decision taken with great risk, they put everything aside to be able to win the Champion League title this season and it would be very disappointing if Inter Milan failed in the final later but what we must also know is that it was a decision taken by themselves because Inter Milan really wanted to win the Champion League title.
In the final later Inter Milan will face PSG even though Inter Milan has eliminated many favorite teams to be able to reach the final but in the final match later everything will be different and I don't see any greater chance for Inter Milan or PSG to win the title, I even think that this is a pretty ideal final for both teams because Inter Milan and PSG have almost the same quality and strength overall this season.
I can understand that after 2010 when they last won it at the Santiago Bernebeu stadium against Bayern Munich they've not won it again ever since then and with also the fact that they again played the finals against Manchester City two years ago and lost it. I my opinion, I felt like Inter Milan actually put in more priority to the Champions league this season than any of the other competitions because how could they lose concentration when they were ahead of their league only to focus more on this one alone. They would have tried to balance both, seriously they need to win this to save their season if not it's going to be a disaster, just imagine from a contender of winning all three competitions to winning non at the end of the season. That's going to be a bad record.