Gold dispenser

Bad, because--paraphrasing Napoleon Hill--"More riches are mined from the minds of men than were ever mined from the mines of the Earth." Your time is the life-force of all the people whom you use it to watch perform their duties---only made "worth" anything when people buy the opportunity to share the time you freely give.

The value of the currency is dependent on the gold reserve of its country. So, basically, we still use gold. Now, if you want us to carry gold instead to use for buying, then, it won't be realistic anymore. Would you rather carry instead one kilo of gold compared to paper bills or even plastics or check?