That's true Chelsea didn't playa against any big team along the way to the final and PsG was the first really big team and they a super game and became champions.
Aside of that I feel like this tournament can't be taken into account to know if the team is gonna be a contender for the Premier league, I feel like a lot of teams didn't play at full effort, Real Madrid was an example of that.
Although Chelsea's opponents were not very difficult until the final, their opponent in the final was the toughest and considering the performance of PSG, PSG was considered the favorite team in the Club World Cup. We had clearly said that the match between PSG vs Real Madrid would be the final match because the team that wins that match will ensure the Club World Cup title but Chelsea proved our idea wrong. However, even if they could not do well in the Premier League, at least they ensured the Club World Cup title so with that confidence they can do well in the Premier League next season. Chelsea currently has several young footballers who are performing well recently, if these young footballers can maintain their good performance, then the team will definitely do better next season through them.