Two serious clubs, they just need to get their transfers right, and Real Madrid has already made a move. Trent is a big signing, but I think they still need one more solid defender personally, i believe Saliba would be a great addition to the team. As for Barcelona, if they keep the same squad, like you said, they could reach the final again. If Yamal keeps performing at the same level as he has so far, that’ll be a huge success.
We can only make predictions but the results can change, for Real Madrid themselves it will probably be much better than last season because they are so serious about overhauling the team by bringing in a number of new players and vice versa with Man City although at the moment it is not clear which players they will bring in.
Barcelona will continue to rely on a number of existing players and in my opinion for next season they will not be able to go further to the semifinals because a number of other teams will also evaluate the players they have so the competition will be much tighter, especially for Barcelona itself.