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.
To be really strong in the Champions League, of course every team must have players with extraordinary talents and that is not only for the main players, but also for some of the players on the bench because when a main player gets injured the team does not immediately experience a decrease in strength in the middle of the season. Barcelona's squad was quite good last season, but for next season Barcelona also still have to improve certain lines to be better than last season. Because when you get to the final the team must also try to win because the defeat that is more painful is losing in the final.
Barcelona lost to Inter in the semifinals only because they were rushing and didn’t take advantage of their chances. Inter relied on their experience and waited until the end. I think if Barcelona had made it to the final, we would have seen a much better match than the one between PSG and Inter. Inter looked very bad and physically unprepared.Regarding the players, as you mentioned, if someone gets injured, of course they need to have good players on the bench. I believe Barcelona’s management will make some very good moves in this transfer window.