I have a Twilio number I use as my Google recovery number (which is only used for that purpose). In my case, it's because I want to protect against SIM swapping attacks on my real phone number, but it also works for people who don't want to give out their real number.

This doesn't work for services that send SMS 2FA codes and the like from a shortcode (as Twilio does not support receiving those), but Google appears to send from a longcode, so it works there.