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.
seeing chelsea's performance in the CWC has shown that their performance is quite improved, because to reach the CWC final is not an easy thing. but i agree that to see their real performance we need to wait to see how they perform consistently in heavier and longer competitions, such as the premier league, champions league, or even the fa cup.
as for the match against PSG, i'm not so sure that they can withstand PSG's attack. PSG is currently on fire and their mentality is very good. maybe chelsea's fate will also end up like real madrid yesterday, humiliated in an important match.
Chelsea's performance remains the same as last season. Indeed, Chelsea already has good strengths, but they weren't consistent last season, and what happened at the CWC wasn't that surprising.
Chelsea still has a lot to improve for next season, and their management is aware of this. We're still seeing rumors of Chelsea recruiting several players, indicating they're serious about developing the team for next season.
Enzo Maresca has been quite successful in making positive changes to the Chelsea team, and that must be acknowledged. As long as he continues his work, there's a strong possibility they can improve even further.