Last year I purchased a ticket to a Broadway show in NYC. I refused to use their digital ticketing nonsense, and when I showed up at the box office just before showtime and said my phone wasn't working (for my own definition of "working") they just handed me paper tickets. So I have to believe every one of these companies must have a way of issuing tickets when people's phones "don't work."
It moves the app one notch back from mandatory, but that's still enough to be a real problem. That method is going to have very low capacity and if you lie about your phone being dead or elsewhere that might screw you over.