Either a dystopia or some kind of hedonistic society where sex just doesn’t have the same implications as for us. A good author can take the most absurd premise and make it seem perfectly natural.
Also note that just because currencies were based on gold very few actually used the opportunity to trade a dollar bill for gold. They bought clothes and food and paid their rent while the gold was a theoretical guarantee that the money would be worth something, and when the gold standard was dropped people didn’t really notice.
