I'm old-fashioned enough to prefer carrying a discrete wallet, not least since my barbershop is cash-only, but also because to forgo it would promote a lost or

I'm old-fashioned enough to prefer carrying a discrete wallet, not least since my barbershop is cash-only, but also because to forgo it would promote a lost or broken phone from headache to catastrophe. That said, I assume even restaurants whose POS equipment is well hidden would be generally able to handle folks who prefer the single point of failure.