Mbappe does not need to prove himself. Because he has proven himself in many matches he has played before. I don't think Mbappe is as happy as he used to be in the French league. PSG has not strengthened its squad like other big teams and the entire burden falls on Mbappe's shoulders. This is something a football player wants, but not every match can handle it.
I think Mbappe's adventure with PSG should end now.
That's it. Mbappe doesn't need to improve himself as he has become one of best player in the world. The only main problem if he is now staynig at the wrong team. He should have moved to a better club than PSG.
There have been many stories about someone achieved many great achievements after they were leaving from their old club which was making them stuck in the same place.
I can also mention some names
Kyle walker
Walker had been joining in the totenham since a very long time ago and he had played in totenham for around 7 years. He has been deciding to leave from the club and he was doing it right. He moved to the city and he won UCL and many trophies in manchester city.
The similar story was also happening with modric. he was also coming from the same club as kyle walker. Modric has wasted many years to play in totenham which was never able giving him prestigious trophy.
Modric was getting three times UCL trophy in a row and he is still winning lots of trophy till now.
That's obviouslty making sense if mbappe will aim to join in the real madrid. Madrid will able to give him higher chance to win the trophy that has not even won it.