0) makes every transaction a trivial SQL query away for the government.
1) everything needs an SMS code. Just as we are trying to get everyone off SMS 2FA
2) doesn’t work for non-Indian numbers or roaming devices
3) can’t get an Indian SIM without proof of address etc. No burners in India
4) regulation expressly forbids devic-local biometrics. This is why there is no Apple Pay in India.
5) Biometrics must be stored with the government. “Unique Identification Authority (UIDAI)” - https://studentbriefs.law.gwu.edu/ilpb/2022/03/22/regulating...