It is very normal and okay to believe that PSG will win the trophy because so far their performance has made it okay to agree to that assumption. For PSG this is a very critical one for them to achieve and they will stop at nothing to achieve it so I don't expect they will perform any lesser than expected of them but they hopefully do not take Chelsea for granted so they don't get surprised in the end.
Yeah, despite the fact that most of us do much believes that PSG will win the final against Chelsea on Sunday, I'm still keeping my fingers crossed because I know this is a game of football and anything can happen. But if we are to follow the way things are, PSG will come out victorious but the good thing is that, we won't be seeing that kind of score line we saw in the Champions League finals Vs Inter Milan. I don't think Chelsea will and can be reduced to that.
This is the first time Chelsea will face a big team in this tournament, and I think that will put a lot of pressure on them, apart from the atmosphere of the final itself. So PSG is clearly better in this regard as they have better morals and mentality than Chelsea. If Chelsea tends to choose to play defensive football, then even though their chances cannot be better than PSG's, but it will not be easy for PSG to find the net.
However, if Chelsea is brave enough to play an open game, then it will make everything easy for PSG to get their win, because even though Chelsea's attack line has improved, but their back line has not, and playing aggressively will make them even more vulnerable.