Defending the title is more difficult, especially since we are talking about the UCL trophy, where this competition is filled with giant teams in the top leagues, only one team has successfully defended this title and that is Real Madrid. PSG is still considered a favorite and may be able to maintain what has been obtained but it is not guaranteed. Madrid, Liverpool, Man City and Bayern Munich have made improvements so that next season the fight will be even more difficult for PSG, including Barcelona with Hansi Flick of course will try to win this title as a top priority.
In last 25 years, only Real Madrid won 4 titles in 5 years with 2014 to 2018 during this time they beat Atlético Madrid 2 times Juventus and Liverpool so for me its never been easy for any team to defend title here in Champions League.
PSG won their first ever title which is good but if they are going to defend they need extra energy and good strategy because now may teams are already done their work for having better results which is surely going to be challenging for PSG which just lost their first ever game in FIFA Club World Cup. Many wills became in front as this is completely different, but things have surely never been easy for having wins in big events while all teams want to win and have honour at the end I am expecting Barcelona, Liverpool and Bayern Munich could be big challenges for PSG in coming season hopefully they could be able to keep their consistency and quality for having better end of their next season.