Won't using e.g. Authy with Gmail for 2FA alleviate the need for a phone number after the initial setup (i.e. requiring a number only once, to initially enable 2FA)?
To you and me 2FA doesn't seem that complicated. But to less technical people it's just overwhelming and they don't want to bother with the learning curve.
For that situation no 2FA solution is going to work.
"Any solution requiring long-term retention of a physical 2FA key or high-entropy secret will not work."
Maybe, on top of that, I'm also arguing with the author. But I assume he implicitly talked about Google (which doesn't provide that option).
Google provides backup codes. You can print them on any kind of paper you want.
Regardless, OP argued that printed backup codes don't work because everything is lost every few weeks.
They get phones from a government program. Each new phone has a new number, and due to the above challenges, it'd be challenging to port numbers and keep a consistent number.
Authy accounts are keyed to your phone number, and to set one up on a new phone you have to receive a verification call/text.
https://support.authy.com/hc/en-us/articles/115001953247-Pho...