Here are the winning chance of each team to become a champion in the next season:
60% for Real Madrid
39% for Manchester City
1% for Arsenal, Inter, Milan, Barcelona, PSG, Bayern Munich, Leverkusen etc.

Real Madrid without Mbappe can still become a champion in this season, so it's no doubt majority of people will believe in Real Madrid.
Those statistics are real and Real should be the favorites but I do have a feeling whoever will win UCL this year , will be a surprise and personally I don't see Real , City or Bayern actually winning it. Maybe Arsenal ? Maybe Inter or Ac.Milan ? Maybe Barcelona ? I think football needs a fresh team to win the trophy to re-gain the confidence of fans to actually love this competition.