Chelsea was more hardworking than PSG in that finals and that's why they kept getting more chances to score goals than PSG, from the kick off till the final whistle the Midfield was dominated by Chelsea and it helped them to connect with their attackers more, PSG tried to penetrate from the flanks but it didn't produce good results since their attackers were mostly displaced by Chelsea's defenders.
It still suprises me cause PSG has a better squad than Chelsea especially in the Midfield and defence bit suprisenly they suddenly became weak, a team that's defeated Madrid, Bayern Munich, Inter, Atletico etc they need to work on their error else it would affect them in the upcoming Champions league tournament.
When a team wins so many titles, they become complacent and that is one of the worst things for a team. Look at City, why do you think they are changing so many of their players? They won 4 league titles with most of these players, but then last season they became much worse, because players already won what they want to win, even a treble, and then they felt like they didn't need anything at all, which is why they ended p with a much worse season last year. They got plenty of players on winter, and now getting now too.
Same goes for PSG, doesn't mean they need to start getting new players, Louis Enrique just needs to make sure that he finds a way for these players to not get complacent and still work hard and not be lazy about it.