Unless there's a kind stranger/public service avaliable, you're stuck if your phone fails for whatever reason. You could argue that there's no excuse to not go

Unless there's a kind stranger/public service avaliable, you're stuck if your phone fails for whatever reason. You could argue that there's no excuse to not go out with a spare charger and all, but I've had my handset just stop working while on the road. I have friends who have had their phone pickpocketed. This also adds on an additional concern as places begin to forego say physical credit cards and IDs in favor of electronic ones that again live on your phone. If that phone is dead, you can't even buy a new one or get money from an ATM. Likely in such a future I'll need to have a redundant phone on me at all times just incase this happens.