Of course, it should be an easy win for PSG and they will take the match serious in order for them to win it. This is because they are very sure of winning this trophy than UCL. Therefore, they shouldn't gamble with their chances of adding this trophy to their titles this season. Inter is a difficult club and winning UCL is a 50-50 chance for both clubs. We can't say yet if PSG would win a treble this season.
Before the match started everyone knew the outcome of this match even though in the history of the meeting of the two teams more often draw, but still Reims this season is just a weak squad. While this season PSG is really ambitious to win titles in any competition and even very eager to pursue the UCL title. So there is no doubt PSG will win in this final match. And regarding the UCL later I still doubt PSG.
Reims didn't even play as though they want to compete the Coupe de France with PSG because they literally gave them the trophy on a platter. Just in the first half PSG scored 3 goals and demoralized the Reims team that is why in the second half they didn't even put energy and PSG felt so relaxed after scoring 3 goals already and they began to Play safely in order not to get any injuries ahead of their Champions League finals against Inter Milan. Playfully, PSG can win the treble this season and create a record for themselves but there is still fear and anxiety in PSG players because they actually know that Inter Milan is a very difficult team to defeat and since they lost the Serie A to Napoli this is the only opportunity they have for them not to go trophyless but PSG might still win them and have a fulfilled season.