I agree, he is still very young, he played with the best players of the time at PSG, why should he regret it? Being at Real Madrid makes him feel better and he will do everything to achieve success at Real Madrid in the coming seasons. Although he started badly this season, he is currently the top scorer in the league with the goals he scored. Maybe if Real Madrid was in better form, he could have scored more goals.
He has chosen his own path, moving to Real Madrid was the best decision for him even though at that time PSG had offered him a new contract. This season he has been unlucky and is in danger of not winning a trophy at the end of the season, but he has been the most productive debutant for Real Madrid.
There will be major changes in the Real Madrid squad after the change of coach, next season they will come back with new strength to make up for this season's failure.
Considering that Real Madrid will compete in the Champions League and Spanish League with a much better squad next year, I think that even if Mbappé's goals are not realized this year, they will be able to get close to it next year. Barcelona managed to defeat Real Madrid in all four matches they played this year and eliminate them from many cups. If Real Madrid beats Barcelona next year, we will watch a different Spanish league. Let's see what kind of an impact Xabi Alonso, who is said to have been signed, will have on the team.