If you hoard currency that is managed by a central authority, then other people can't obtain currency for their productivity, and thus can't consume market goods. (This is essentially what caused the Great Depression: wealthy people hoovering and hoarding currency, poor people getting no income and spending)

If you allow anyone to create currency by creating IOUs to buy stuff (which sellers can choose to accept), and you mean that the sellers create and accept that currency, then yes, hoarding is not much problem for overall society, until and unless the day when past hoarders rush to market at the same time (when they run out of durable goods or other income) causing sudden inflation.