According to Peter L. Bernstein’s The Power of Gold: The History of an Obsession (a book I’d highly recommend), fractional banking has its origins in scams perp

According to Peter L. Bernstein’s The Power of Gold: The History of an Obsession (a book I’d highly recommend), fractional banking has its origins in scams perpetrated by goldsmiths, who’d issue promissory notes for more precious metal than they had in stock. Once they saw how they could utilize it for its own purposes, European governments legalized what was previously a widespread criminal practice. So if governments end up appreciating this particular “scam”, crypto might conceivably (although I personally doubt it) go through a similar process in the future.