imagine a future where restaurant grade tables themselves have some sort of QR code where you can “just leave the money on the table and walk out” 

 Amazon tried that with stores

 

 I like the dash cart 🛒 https://www.aboutamazon.com/news/retail/amazon-dash-cart-new-features-whole-foods 

 I have already seen a version of this with QR codes on receipts to pay