It looks like the degenerates trying to pump CBDC's have written a paper saying that fungibility (singleness) in paper money doesn't actually matter as long as you regulate hard enough. Bitcoin fixes this

King's College London

Single-minded? Rethinking our approach to the 'singleness of money' could help to reap the benefits of stablecoins | King's College London

The anticipated change in policy towards digital assets in the US under President Trump, December’s Stablecoin Bill in Hong Kong and January’s ...