Its not socially acceptable to say in public that you don't know how to text, so SMS 2FA has zero help desk support costs. It is socially acceptable to say you

Its not socially acceptable to say in public that you don't know how to text, so SMS 2FA has zero help desk support costs. It is socially acceptable to say you as a revenue generating customer don't know every little detail of TOTP, so the help desk for all practical purposes has to become a TOTP app help desk and provide support for every app ever written and every use case imaginable including device upgrades, etc. There is no upper limit to technical support. "Your helpdesk told me to install this app and now my battery is dead I demand compensation" TOTP is pretty expensive to implement.