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.
I agree with your assumption that Barcelona is the best team in the world right now, but Barcelona is the best team from La Liga. If you talk about the best team in Europe it is Manchester City and this season Barcelona is not one of them.
There is no better team in La Liga this season than Barcelona. The two titles they have won this season are proof that your assumptions about them are very weak, but of course only about domestic competition. I even really doubt how you came to that conclusion, I think you just don't want to admit it.