Real Madrid very rarely loses in the Champions League final, if one expects Real Madrid to fail to win the title, then don't let them reach the final. Real Madrid can almost always be guaranteed to win the Champions League title every time they are in the final, it is not a coincidence or luck, but a tradition that we often see as a reality.
But can Real Madrid still be beaten? Of course you can, but it's really hard to expect them to lose in the final stages. The Europa League Final and the FA Cup Final teach us something, that not all favorites can win.
Madrid certainly have everything they need to face the final later, mentality, performance, and also the quality of the team to face Dortmund later, but still it also cannot guarantee they can beat Dortmund easily later, especially if we see in Dortmund's journey to the final they managed to beat a favorite team like PSG who did have quality and also better performance than Dortmund, the Champions League final is a prestigious final and of course the tactics and strategies applied by both coaches can be the difference and determinant of victory from both teams in the final match later.
I think the Europa League final a few weeks ago can be our reference to no longer tend to make the favorite team as champions in the final match, because there is really no team that cannot be beaten so far even though no matter how great the team has been, no matter how great Madrid is at this time, of course there is still a gap for a team to beat them, Moreover, we know that Dortmund certainly also has the motivation to be able to beat Madrid and of course to win the Champions League trophy in the final match later.