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.
Who's taking the EPL side for granted? They easily forgets how the football world operates? Everyone might been be underestimating the stats of Chelsea simply because they've been trying so hard to get back on the winning lane but all time is not lost, the Blues can still work some magic out. Come to think of everything, who would have thought about Chelsea actually featuring in the club world cup grand finale. Nobody can believe them but they just need the continue with hidden stellar performance, building from route and becoming a comfortable team.
Chelsea is not a magician and they don't have what it takes to perform any magic against PSG. Chelsea will likely accept defeat and wouldn't be able to stretch the match to an additional 30 minutes extra time. I feel a lot of Chelsea fans will be disappointed after the end of the match because they don't want to accept the fact that PSG is better than them.