Adding to what has been responded to you, which day status of Liverpool for the past few seasons, I no longer see them as serious contenders for the Champions League. The lost their ability to contest effectively in the Champions League when they lost Sadio mané. We must come today realization or understanding that there are many other good teams better than Liverpool. For instance, Dortmund and Leverkusen are to me better than the Liverpool of today.
As Doomloop observed, Liverpool just changed their coach, you don't expect them to continue with the momentum of Klopp. It is possible that the momentum could and if care not taken, drop low before they could rise again.
I think it is too early to conclude that Liverpool is not strong enough to compete in the next Champions League. It may be difficult for the new coach to continue with the level of Klopp but Liverpool can perform at the top level again. Honestly, most of us believed that Liverpool has a chance to win the treble under Klopp this season. But their performance got worse and lost two trophies due to the injured players. I agree with you, Liverpool struggled with their games since Sadio Mané moved to Bayern Munich. Of course, Dortmund and Leverkusen are far better than Liverpool, by their impressive performance this season.
Mbappe would not have won the Champions League title with PSG. Mbappe came to Madrid to win the Champions League title. There is no team more experienced in the Champions League than Real Madrid. Also Real Madrid team is very stable. With the help of Ancelotti, Mbappe can further improve his overall performance.
Mbappe is a player who has the ability to score a lot of goals. Real Madrid's midfield is very experienced. If Mbappe is able to adapt easily to the midfielders, then I believe Mbappe will be the top scorer in La Liga next season.
Mbappe did not join Real Madrid to win the Champions League alone, most importantly, Mbappe joined his dream team from childhood. Mbappe's dream is to play for Real Madrid one day and with patience, he has achieved that goal this season. However, Mbappe expected to win the Champions League trophy with PSG this season but that didn't happen, as they got eliminated by Dortmund in the semifinal. Joining Real Madrid was Mbappe last chance to win the Champions League trophy in his career, and I believe that will be possible next season because he will strengthen their performance.
Mbappe will easily adapt to the club since he will have enough time to play. Mbappe will probably be the top scorer in La Liga next season because Vinicius and Rodrygo will make things easier for him.