For El Clasico, it will still be very interesting.
Barcelona's loss to Arsenal won't prove that they're bad because it's basically just a trial and see what players they bring in. It's just to try out some players so that they can adapt more and Xavi wants to see if there's potential from young players or not.
Of course, exactly..
a friendly match will be very different from the real El Classico. Usually in friendly matches, each club will not play very insistently and optimally to show that their team is better. because they are aware of the risk of injury that may also occur in pre-season. This will not be good for these players. Because usually in friendly matches, the coaches don't field their core players 100% full time. There will definitely be a change of players with the coatings. This is also an attempt to test their overall strength later, at least it should be like that. And when the season really enters, they can be many times more optimal. And this is completely different when El Classico, Barcelona will try their best to be as optimal as possible, as well as Real Madrid. Not only the goal, but the prestige, euphoria, and also the efforts are very different between friendly matches and real matches, especially El Classico later.