I went to the Love Yourself In Seoul concert films and watched a few clips here and since I regularly interact with ARMYs who speak in languages other than english, I have different perspective.
Various ARMYs traveled all over the world to attend BTS concerts and can often feel overwhelmed because of the local language used. For example, I can read in 7 languages, out of these 7 I am fluent in 3 and can understand 5 spoken.
BTS seemed to have a language coach whenever they are in one country to help them practice for their fans. For example, In Saint-Denis (Paris), Jimin french words were very closed to the ‘standard french’.
BTS seemed to focus on 2 languages on concerts, the official local language of the country they are in and Korean which generally translates to the local language.
This can decrease the concert experience for foreign fans.
There was a Brazilian interview that I watched ( I really struggle to understand Brazilian Portuguese so it’s not very clear), parents, not young fans, had been sleeping outdoors for two days in line to buy BTS concert tickets for their children and themselves. These parents were often crying, hungry and exhausted.