Even at their worst, Real Madrid always be a team that any club in the UCL will be wary of. In the Ancelotti era, they played pragmatically, they still won trophies.
On the other hand I wouldn't blame those who are a little dubious about the new coaching under Xabi Alonso, it's because Real Madrid players are not used to a coach who has a system. So at this stage, Madrid are still in experimental mode, which requires Xabi to gradually change the habits of the old style of play to the style of the modern era.
In the last two seasons under Ancelotti, they have also managed to win the title despite Real Madrid having suffered injuries to several key players, except for the previous season, which was a complete failure. Real Madrid is one of the strongest teams in Europe thanks to their experience and mentality, so whatever the situation, this team will remain a title contender. Xabi Alonso is a bit of a doubt, but if given the trust, I'm confident he can lead Real Madrid to success. Although his first season won't be easy, he needs to adapt to the new system he's building.