I can't believe economists are still telling the Just So story about cash money emerging from barter economies. A story that was thoroughly and quite publicly debunked by David Graeber in his 2011 book Debt. So even more disappointing that there are still journalists accepting it without question. Here's a recent example from the RNZ podcast The Detail:
https://www.rnz.co.nz/programmes/the-detail/story/2018861441/what-makes-a-dollar-determining-the-value-of-a-currency