My dad finally retired his 2008 flip phone last year, but before that a QR code would have been no help to him. I visited them recently, and not a single restaurant (business at all) had QR codes in their town.

Probably depends on where you are, I’ve only seen that option once or twice, and that was in addition to a proper menu.

I've only seen QR code menus in big cities and the southwest U.S.