If the dollar is a good medium of exchange and store of value, I have no need of gold. Dollars are considerably more convenient. But if the dollar isn't a good store of value (or I suspect it won't be in the future), then I can use gold as a store of value, for the reasons you stated. Gold therefore becomes my alternative to currency. Functionally, it's almost a short on currency.
But the currency has to be fairly bad for this to work. Example: Gold was $1700 maybe five years ago. (Can't get exact dates from Yahoo Finance's current site, so I'm working from memory.) It fell to $1050 maybe a year ago. Now it's $1200. That makes the dollar look like a pillar of stability.