Installed Steam on a new computer. Signed in. It sent a passcode to my GMail. I signed into GMail. It wanted me to 2FA because I hadn’t signed into Google on that device. It sent a notification to my phone, which I never received. I had it resend the notification twice, still nothing. Tried again with my phone’s offline passcodes. Neither worked. Tried the QR code/Bluetooth connection, and that finally did it.
At least I got through in the end, but fuck, it’s annoying.
VoIP is not supported for 2FA by some institutions like banks because it may be less secure than a conventional phone line, since it is connected to the internet. In practice, I think SMS is insecure regardless whether it is over the internet or phone line, but in any case that is why VoIP is not fully supported.
SMS is very unsecure but companies use it. I think that’s what Discord uses on sign up, but they don’t allow free numbers like Google Voice.