It's weird that people are sleepwalking into this single point-of-failure dystopia instead of regulating it out existence and only realize it when their phone gets damaged or lost or is glitching in some deal-breaking way.
Here's a tip, if you want people to help you out don't start with, "I don't have an smartphone..."
Instead, say a variation of "Hey, my camera's broken/the app keeps crashing on my phone. Can you help me out?" People tend to be a lot more sympathetic.
I've never had issues with the restaurant QR thing.
me:"Hey, my camera doesn't work can you help me out?"
waiter: "Sure you can take a look on my phone/use this tablet."
Like, I have to fix my phone's camera before I can park in your city? are you kidding me?
If opening a new account, pretend not to have a phone.