GA floor in arenas is definitely thing in the states, I guess at some point people said The Who thing was in the past. I mean, I can see putting seats on the floor for say Slipknot ending in a disaster of chairs everywhere. So I think it can go both ways from safety so it seems from my experiences, seats on the floor of an area vs. GA is an artist choice. For example, Iron Maiden at Barclays, Disturbed at MSG, Greta Van Fleet at Forest Hills Stadium all had big GA floors this year, meanwhile Kiss at MSG, Elton John at Staples Center, and Aerosmith at Park Theater all had seats on the floor. Now that I think about it, another reason could be $ as those front seats are so insanely expensive for those last three bands I listed.
Either way, when rock bands play these mid sized theaters, which DT typically plays, it always seems to become a "do you sit or stand?" question. Incubus at Warner THeater two weekends ago, the band hits the stage and I could see everyone in my section looking at each other as if do you sit or stand. I stood and then literally everyone else did. It was like they were waiting for someone to make a move first. It's so funny in some ways, but really kind of bums me out mostly that it is even a thing.