How was Barcelona the favourite for the Champions League last season. There can never be only one favourite for it. If you had said, Barcelona were one of the favourites then it's very valid. Liverpool was seen as one of the favourites but exited earlier in the competition. PSG was one of the favourites as well, same as Bayern Munich too. All I'm saying is that, there cannot be only one favourite, there's always two or more favourites to win a competition.
UEFA Champions League this season, none of us expected Paris Saint-Germain to come out to win it because they just lost their best player, Kylian Mbappe to Real Madrid and the manager, Luis Enrique was simply gathering his plans but look at him now, he's more confident to take the club to next level.
Favorite clubs are the teams that are under high probability to win the UEFA champions league and Barcelona fall in this category. Let's be straight, Barcelona was more focused and seen as a club that will reach the grand UCL final but ended up been eliminated in the UEFA Champions League. Barcelona did their best but got knocked out in the last minute by Inter Milan, the same team that got humiliated by Paris Saint-Germain 5 nil in the UCL final. Football is filled with mystery.