I went to a bar that only allowed ordering online, either through an app or through a website, but either way, they couldn't just take an order and punch it into their system. I looked over their draught beer menu and they didn't have the beer listed, that I saw on the tap wall and wanted. I asked the bartender how I could order that specific beer, and he said I couldn't if it wasn't in the app. I asked if I could order a beer of the same price and just tell him directly that I wanted the other one. He seemed confused and/or unwilling to do that.
I walked out and that was the last time I had any involvement with a bar or restaurant that went app-only.