I don't think those work with today's code generators, since nothing is ever sent to the user. SMS and other types of 2FA should hopefully be obsolete soon.
Ha, not if they won't let you make an account without one in the first place. Looking at you, OpenAI asshats.
The only ones I've seen still use SMS confirmation are banks, not so much because of advertising because they already have just about every shred of info that's possible to get about you without sequencing your DNA, but because they're too cheap to overhaul their systems.
