You’ll note that most people purchase things with credit cards and checks. Trying to buy your daily latte with a gold coin will get you some very strange looks and a manager trying to figure out what to do.

Things like that are more closely associated with heist movies (or their more mundane analogue, "used notes", with run-of-the-mill crime) than legitimate commerce.

After the 1982 curtailments, bearer instruments practically don’t exist in the US.

As for gold, gold is a commodity, and one that has industrial utility. You can use it for things, so of course, it’s not particularly controlled.