This is mitigated by the fact that iPhones have power reserve for 5 hours for even after the phones main battery is depleted. This is how Express Transit works

This is mitigated by the fact that iPhones have power reserve for 5 hours for even after the phones main battery is depleted. This is how Express Transit works — you can tap your iPhone to pay for your subway ride even when your phone is dead. https://support.apple.com/en-us/HT209495 https://support.apple.com/en-us/HT209495 One might argue that even the reserve power might run out on a really long flight, say like a SIN-JFK. But most travelers these days carry battery packs so it’s not a big deal. Even if they don’t, a neighboring passenger would probably have one, and a few minutes of charging should suffice. But in reality I imagine this would be more useful for shorter/frequent cross border trips like say at the US Canada border. For longer trips, most people would probably still want to carry a paper passport as a backup. Phones can fail for many reasons. Boarding passes are already largely electronic in the US. It’s been a few years since I’ve had a printed boarding pass. Plus all you need to reprint your boarding pass at a kiosk is your record locator. This is largely a solved problem.