Yes, it is actually very interesting. Barcelona has won more Spanish championships than Real in recent years, but Real is much more successful than Barcelona in the Champions League. In the last 2 years, Barcelona did not even manage to make it to the knockout phase of the Champions League. I really don't know how to explain it rationally.
Barcelona has had major financial and organizational problems in recent years, and the loss of Messi was irreplaceable.
Honestly, I don't see Barcelona as one of the favorites in the next season of the Champions League, unlike Real.
Manchester City remains the main favorite for the next season of the Champions League.
Since 2015, Barcelona never won Champion League tittle and the best achievement lead until semifinal stage, but tragic last two season under Xavi Hernandez era Barcelona have been eliminated from group stage. Its seven years Barcelona can't win Champion League tittle and difference with the rival team Real Madrid success dominance become the winner in several times.
Talking about next season, seems Barcelona is not favorite team exactly when facing bigger team like Bayern Munich or Inter Milan in group stage. Can't guarantee for Barcelona has good performance in domestic league get impact in Champion League, this season Barcelona success winning La Liga and become fewest goals conceded teams but in Champion League Barcelona conceded many goals on group phase. Lest see with Barcelona participants in Champion League next season, will fail reach to knock out phase or success lead until final stage.