Barcelona is not the best team in the world at the moment, even in the previous season they did not deserve this title either.
As an illustration, as you said, the Champions League, which is the league for the top teams, Barcelona cannot get a good position there and is still below Manchester City.
The two trophies owned by Barcelona cannot be used as a guarantee that they are the best team.
Barcelona is no way the best team in Europe but did you just say Barça don't deserve the league title they won? Really? A team won the league with about 4 or 5 games to spare and yet they don't deserve the league? They won the league with like 13 points but you said they don't deserve the league? Oh c'mon! I agree Barcelona have been poor in Europe and that's not excusable but they 100% deserved to win the league. They only started dropping points an conceding goals after they had won the trophy already.
No team in La Liga deserved to win the trophy more than Barcelona. Despite their injuries they still managed to win crucial league games and won the trophy. Please, give Barcelona their floweres because they deserve it.