Also if your public SMS reset number is in google voice, a hacker can't port it off of Google easily because you need to log into your google account to port it

Also if your public SMS reset number is in google voice, a hacker can't port it off of Google easily because you need to log into your google account to port it, which requires 2fa. They have to figure out your real number, but you never give that out to anyone or you just use google hangouts SMS instead of forwarding text messages to your insecure phone.