It is difficult to get a crypto proponent to understand something, when their crypto wealth depends on them not understanding it. EDIT: If you steal my gold or other metal store of value, I can pursue you in court and recover my loss (either the actual materials lost or fiat value). If you steal my single named security, I can pursue you in court and recover my loss (or the clearinghouse will reverse the transaction)…
FWIW, I'm pretty sure banks loose in the hundreds of billions per year to fraud... and it's all heavily regulated.
[1] https://www.federalreserve.gov/supervisionreg/regecg.htm
[2] https://www.federalreserve.gov/boarddocs/supmanual/cch/efta....
[3] https://www.businessinsider.com/huobi-global-warrant-seeks-1... (A Coinbase user lost $11.6 million in under 10 minutes after falling for a fake-notification scam, the US attorney's office said)