Oh, God... don't even get me started about fucking Ticketmaster and their goddamn app.
I've had multiple venues just straight-up tell me "no app, no entry" when I've contacted them pushing-back on installing Ticketmaster's drek.
For one I was able to play "confused old man" and get printed tickets, at least.
For another I just gave up, swallowed my morals, and loaded their app on my wife's iPhone.
There was one that I just didn't buy tickets for. The performer didn't really need my support, and I wasn't super broken up to not see them, but they lost a sale because of the stupid app requirement.