You're right, it's insane how badly smartphones have fucked up concert experiences. Luckily I barely notice it myself since I always try to get into the first row (or, in this case, a good spot in the stands) and therefore don't see much of what's going on behind me. However I was recently at a heavy metal show in my hometown, and right behind me there was a middle-aged man filming pretty much the entire show, almost all 90 minutes of it... that does bother me a lot, I don't really see what's the point of even paying to go there if you're just gonna film all of it. Film some parts, or in my case one full song? I think that's fine as long as you don't disturb other people's experience and enjoy the rest of the show not being glued to your phone, it just shouldn't take over everything.