We humans are sinful beings we'll make idols out of pretty much anything and everything. That doesn't mean that those things are themselves sinful including currency, as you've pointed out earlier, but that it's our behavior towards them that is the sin.
Some people serve and worship their wardrobe, but it's not sinful to wear clothes, some serve and worship their career, but its not sinful to have a job.
As you point out most serve and worship money, but that doesn't mean it's sinful to have money.