What do we think about secondary phone for 2FA?

I wish I could find it, but I remember reading about how someone bought a burner phone (in cash), and was able to forward all the texts from it. Only the services that use it for 2FA know this phone number as it isn't used for anything except receiving 2FA codes. Yes, it is still vulnerable to SIM swaps but that is only after the hacker knows the phone number. Not 100% but it creates a barrier. Secondly, it is …

2fa phone privacy