Both are excellent coaches. Ancelotti has proven himself many times, while Xabi is just starting his career. I think Xabi has great potential for the future because he is still young. Their playing styles are also different; Xabi relies on a style that prioritizes ball possession and attacking. Unlike Ancelotti, who focuses more on combination plays and doesn’t prioritize ball possession.
Ancelotti is one of the best coaches of all time, with extensive experience and a flexible philosophy, enabling him to handle teams with various characteristics and win major trophies in different leagues. Therefore, Madrid should give him more time. At least three years should be enough for him to build better trust with the fans and management.
I don't want to downplay Xabi's achievements, but compared to Ancelotti, he is only at the very beginning of his journey and he still has to prove how good a coach he is. He created a small miracle with Bayer, but he couldn't repeat it in the new season, and Real is a completely different level and I can't say yet that he is ready for a team of this level, at least if we evaluate his work in the Club World Cup. In La Liga, there is Barcelona, which is in excellent shape, so it will be difficult for them in La Liga too.
Xabi Alonso will have to start the new season in a challenging way because the expectations from him are sky-high just like the fans expected from Ancelotti. As soon as he takes charge of big clubs, he will have to be ready to face the pressure and criticism and continue to try to restore the team tradition. Real Madrid could not fulfill any of the expectations from last season and the experienced coach Ancelotti was forced to leave the team in the face of criticism.
New coach Xabi can take credit for bringing the team to the semi-finals of the Club World Cup at the beginning but this may not have been enough for him. Although the team situation seems much weaker than at any other time. I think Real Madrid may be ahead of Barcelona when compared to the Club World Cup but Barcelona is in a strong position overall.