That seems a bit... excessive? I'd assume you'd just need two debit cards for two different banks that offer ATM fee reimbursements, like Charles Schwab and Fidelity. Keep one in your money belt and the other in your pack that you normally keep in your hotel room. Barring some crazy sudden regional disaster, I'd expect you'd always be able to pull whatever cash you need from an ATM on any given day. Although the VISA system did go down (https://www.theguardian.com/world/live/2018/jun/01/visa-outa...) while I was on vacation in London last year, so there's always the possibility of that, I suppose.
It really wasn't that long ago that smartphones and tablets didn't exist, and hundreds of millions of people still managed to travel by using printed maps and asking local people for directions. I think that still works?
Power outages. Natural disasters. Civil unrest. Account freezes. Erroneous government investigations. Travel fraud alerts. Big crowds that result in empty ATMs. Cell network overloads. Strong magnetic fields.
There are a million common ways that access to cash can be impeded. Carrying a small extra wallet is no inconvenience whatsoever. I’m not sure why it would count as excessive. I think it is insane and massively short sighted to rely solely on cards. I bet I could find thousands in Puerto Rico who agree.
Nevermind privacy - it’s possible I would like my real-time location and purchase history to not be reported to the USA intelligence community in real-time, occasionally. Cards do this as a matter of course.
I don’t have paper maps, and carrying offline digital copies of maps of the regions in which I intend to travel on all of my devices is quick, easy, and convenient.
It really wasn't that long ago that smartphones and tablets didn't exist, and hundreds of millions of people still managed to travel by using printed maps and asking local people for directions. I think that still works?