I tell folks this all the time.... Good luck spending your gold at a gas station. Chances are I can use my bitcoin for a Walmart gift card and use it for gas if need be....
Gold doesn't need electricity or computers to work, much less the cooperation of Walmart and whatever big corporation is managing their gift cards for them, and whatever company the gas station uses to process gift cards.
Walmart is nation wide! So, your bringing a scale and a way to chip pices off your $2000 coin for gas? Oh no, my phone doesn't have service.... McDonald's, Starbucks and many other places have free wifi. Oh no, it's the apocalypse and all wifi is down, chances are you'll get beat down or shot at the gas station for your gold as your holding up the line with your gold in hand trying ro barter with the cashier!