Inter is way on the different level. They beat the winners of La Liga and Bundesliga that can't be compared with PSG, which was beating the weaker teams than them. So, it totally makes sense to argue Inter is clearly a bit better, though the odds said the opposite. It only reminds me with Europa League final when Tottenham gets bigger odds, but win its first european trophy.
Your analysis is flawed. If you want to look at it that way, PSG also eliminated Liverpool, which happens to be the English champion. However, none of this is important. The final game is a feature between two good teams and a winner will emerge. Inter Milan may have the edge because it has won it before and has more experience in the competition, but PSG has also been amazing this season and I'm not writing them off.
I totally agree, we can't judge the final result based off inter milans performance when they played against Barcelona. No one is disputing the fact that Barcelona were not relentless to win and that they did well this season but Liverpool also had a good run like Barcelona and psg was still able to eliminate them. There are reasons why the odds are in favour of psg to win but for now it's hard to predict who will win