I think its a mixed bag for smartphones at concerts. Some ban them, some will stop and say "hey guys be present, I get it but lets just have one person film and they will post it" (something Justin Hawkins of The Darkness did recently), some just have a sea of phones and no engagement (saw footage recently where the band had this big light show, forget who, that was filmed from the back and it was just bored looking people with their phones out), and then you have a handful of phones recording but everyone else into it to where it's chaos and the video makes you seasick from the chaos and the audio is shit because they are too close for the PA to work properly and you just get the bass and can't even hear the singer or they zoom in and the audio pickup changes (I watch a lot of fan videos from Die Spitz performances, and some of those are just focused on Kate while occasionally panning over to Ava or Ellie or when Chloe switches with Ava.). Hard to have your phone out when the pitt is swirling or when people are crowd surfing.