[runevault]

Some services don't allow GVoice 2fa. I tried it for instagram because I refuse to give Facebook my real number and they rejected it.

[dpkirchner]

Same, although my goal was to use a Google Voice number that could be shared amongst a team, for integrating with Facebook's APIs.

[realAzazello]

Agreed. Definitely some USA banks do not (with one of my accounts, neither the SMS nor the automated call would come through the GV number), and although a few years since last I tried, craigslist would not accept GV for account verification.