I think only Real Madrid, Man City, and Bayern Munich that have bigger chance to win UCL title. I'm sorry I exclude Barcelona because it seems hard for Barcelona to win UCL title with their current condition. Mbappe should move to those 2 teams/clubs if he wants to have a good chance to win UCL title in the future. However, I think Real Madrid is still the best team in UCL which already wins more titles over other teams. Real Madrid also has a great coach and potential players to be stronger clubs in the future.
PSG will be always difficult to win UCL title because they have no proper mentality to win it. PSG has no player who can influence other players to play consistently during the match. It is the role of the captain team or the senior players who have a lot of experienced in the competition.
In fact, I don't dispute what you said because it is true that these 3 teams are stronger than the other teams. Every team still has the same chance, In fact I will not exclude any team because we are only in the round of 16, Of course the journey to the final is still quite far. Even for PSG, they are also classified as a great team with lots of quality players in their team so they cannot be considered weak this season. For barcelona, Of course they are not strong enough if you look at their game in the group phase, But I think they will improve their game to be better in the round of 16.
For the defending champions, Manchester City is still quite the favorite to win the UCL trophy again this season. For this reason, We will see the candidates compete strongly in every match they will play this season. So, If one of them fails in the round of 16, It could be in the Champions League this season,Tthere will be many surprises that will happen.