The next matches may be more difficult for Madrid and the opponent team has the impression that their defense is much weaker and we will have to wait and see how quickly they can get back to their strong position. I think Mbappe's performance is relatively good but he fails to display the right play due to a lack of coordination with his teammates.
With departures of Kroos, Casemiro and ageing effect on Modric, Real Madrid have more problems and weakness in their midfield. With many injuries in defense system on their defenders, Real Madrid have big systematic issue in defense and whether they succeed or fail to cover their defensive weakness, will decide they will win titles like La Liga or Champions League in this season.
They still have many world class attacking players and very powerful attacking system, but as a team they need strong defense to win matches, then win titles. Mbappe is only an attacking player and he can not decide result for a whole team, this big final defeat is an example and also a very big warning for Real Madrid.
Yea, it's actually a big warning for real madrid because their defense can't be conceding such cheap goals and be expecting to win something big, if you look at all the teams that has won the league and the uefa champions league over the years, you will observe that their defensive performance is above average because their are some games they wouldn't be at their very best, so it's their defense that mostly save them, and sometimes it is very important that their defense is strong enough to close out games, so fixing their defense is one vital area of the team Carlo ancelotti needs to fix, even if it warrant him to go into the transfer market to do that.
Then as for the departure of Toni Kross, casemiro and now Luka modric that is almost done with his playing career, real madrid are not just weak in midfield, they also lack the quality that Kross especially brings to the team, because he was just like the conductor and dictator of their play, so his departure is still felt seriously in this real Madrid team even till today, so that's another area they seriously need to address in other to stay competitive in the league and in the uefa champions league.