#2 Real Madrid's transition

After total European dominance in recent seasons, Real Madrid are in a state of transition, following the sale of Ronaldo to Juventus, and the resignation of Zinedine Zidane as coach, and the team might struggle in the coming season.
https://www.sportskeeda.com/football/3-reasons-why-real-madrid-might-struggle-next-season-ss
Ronaldo's goals and charisma will be impossible to replace at Real Madrid, and while it might motivate other players to raise their game and take Real Madrid to the next level post Ronaldo, nobody else can deliver in the manner he did.
Zidane's departure also poses a serious conundrum for Real, as the Frenchman found a way to balance his squad of highly competitive and egocentric players, rotating them and achieving unprecedented success (having been a galactico himself), but the appointment of Julen Lopetegui who has minimal European experience could be counterproductive.
This will be a blessing to Barcelona, because Real Madrid is the biggest threat to their quest to win the Champions League, owing to the familiarity between both clubs in La Liga and Real Madrid's recent pedigree in the competition.
If Real Madrid fail to perform to their usual high standards in the Champions League, then Barcelona would have one less contender to worry about.