Allowing SMS
Makes sense in India for the 1.0 version of this. It isn't ideal but 2FA w/SMS is no less secure than the 1FA currently being used by many, and importantly there appears to be no REQUIREMENT for a given bank / payment provider to support SMS as a 2FA option. India still has millions using dumbphones that don't support dedicated 2FA apps, for them SMS may be the only option for now.
Get people used to 2FA, work out all the issues (such as introducing dumbphones offering a proper non SMS 2FA solution, or maybe used low end smartphones become the cheaper option and the dumbphone category disappears entirely) then you can announce a date after which SMS is no longer permitted.