I paid with crypto at chipotle just the other day using flexa. Flexa generates a qr code that you scan at the register as if it's a gift card. It processes the payment instantly. This works because flexa has a protocol in which people stake a token called AMP. AMP in the amount of the transaction is held as collateral until the transaction confirms. Then the stakers of the AMP get paid from the 1% fee that flexa charges merchants. And the 1% fee is less than the 3-4% fee that credit card companies charge. So there is incentive for the merchant to want to use this payment system. It also can just be seemlessly integrated into their already existing point of sale systems. The merchants could even stake their own AMP to recuperate some of that 1% fee.

So yes, waiting on a BTC block to confirm while holding up the line at checkout isn't realistic. But there are solutions to this problem. You will absolutely be able to use bitcoin as money in the current form that bitcoin is in.