Asia has a very unique financial system in this sense. They are not reliant on 3rd party payment processors that can be counted on one hand, and they usually support P2P payment between banks. They also usually prefer to use QR than NFC (like on wechat, line, and kakao). This is one example standard that I found from Indonesia called QRIS, and they are expanding it wherever they can. Of course Visa is upset about those lol (see the section about US Government response)

https://en.wikipedia.org/wiki/QRIS

For once I am with apple on this one. The bad thing about passwords is their randomness. Humans are not very good at remembering very big entropy

This is borderline virus that eats up user ssd write cycle

I prefer reticulum. They make it so the network is independent of the physical layer. You can even use old AX.25 modem if you wanted to. Which is what I did. I basically use MCU to be a modem and use 3.5mm jack to connect it to any amateur/HAM radio

IMEI and GSM in general is one of those “industry standard” that are so heavily paywalled that the effort to reverse engineer it is pretty hard. You can look at osmocomm, the umbrella open source project that tries to make mobile communication more accessible and open

Sure you can only determine if “user is of age or not” with zero knowledge proof. But collect enough proof and statistics can de anonymize that anyway. How is no one addressing that?