1) Most people do not have smart phones.
2) Some people just hate technology and do not want to bother using their phone (country boys/farmers). They rather take the plastic out of their wallet and use that payment system.
3) Old people would not be able to adapt to the QR code way. My 70 year old grandmother would never figure out how to setup a bitcoin wallet on her phone.
Some kind of handheld thing is needed for Bitcoin. Hardware wallet could be a option, but I personally think a simple plastic card would be the best solution.
The truth is most people who use phones to text and check social media won't have enough battery power left to use it for bitcoin purchases.
Oh my gosh! You are so right my friend! Social Media makes me sick....
People just love throwing their personal information away! Goodbye Family Vacation Photos Taken in Mexico! You now belong to the internet forever!