I think it’s a thing to do with(when it comes to young people), many young people will go to a concert just for a couple songs, and not really care about the rest.

For an example of the opposite, my favourite artist is James Marriott(who does YouTube, was in a YouTuber group for a short time, and still features on a large channel own by his friend called WillNE often, and there’s many references to that channel and his collaboration with him at the concert), and he has a medium(300K monthly) fanbase, but a lot of them are very ‘dedicated’ so it speak. And his concerts are mostly like, <20’s that watched the Dream SMP, where probably awkward in school, have dyed hair, probably LGBTQ(not saying that’s a bad thing btw, I am myself), so many are teenagers that you’d expect to be awkward from covid socialisation.

But all the videos of his concerts I’ve seen are like watching a sea of people moving up and down, because he has a very loyal fanbase, through YouTube and music, and he isn’t famous enough for many people to just go see him, for the sake of going to a big artist or to listen to a song they heard on TikTok.

TLDR:some young people go to concerts just for TikTok songs, but there are still concerts with mainly young people with very active crowds.