I can't say if Chelsea has improved in their performance or not, it's when the new season starts is when we would know. However, their performance in CWC is impressive and their fate will be tested in the finals when they play against PSG who have destroyed and humiliated top big clubs in various leagues in recent times.
Chelsea's performance is okay with what I’ve seen from them in this Club World Cup; they made it to the final, which is a reason for us to say Chelsea's performance has improved. Their main focus now should be against PSG because PSG is now a beast. Regardless of how strong the club should be, they are afraid of PSG at this point because they are in good form, and their performance is now even in doubt. They can beat the hell out of Chelsea if Chelsea does not do well in that final. As for this, Chelsea should be well prepared for this match to avoid being shamed.
However, I’m even eager to see Chelsea's performance next season because their signees are going to do everything to see them shine in the next season's competition. However, next season is going to be tough because every club is getting prepared ahead of it.
If I was a Chelsea fan I won't be bragging about that finals because of the team I'll be playing against they shouldn't forget that their opponents are the Champions of Europe that are doing every possible to add to their trophy and merit being called the best team in the world. I'm not saying it's impossible for any team to win them yes it's possible but we're talking about PSG here a team with the best squad and manager in Europe the previous season.