> It is also handled quite well already, as modern people have credit cards in their wallet, in their phone and on their watch. So there is already a 3-way back

> It is also handled quite well already, as modern people have credit cards in their wallet, in their phone and on their watch. So there is already a 3-way backup that needs to break. Personally, I'd not use the word 'backup' if you can lose all three in a single accident. Also, these are just different forms of access, none of these would work if the infrastructure is down. It seems you dodged my points. I'm not advocating for cash, more like warning that an online-only system isn't resilient enough in the first place. In the scenarios I provided, if cash doesn't exist (as per OP wishes), the only solution I see would be going back to trading goods/services. What valuable possession/skills does a person have.