I lost my work Gmail account several years ago due to this and vowed never to go back to Google. It was a slow decay, though, where over the course of a few mo

I lost my work Gmail account several years ago due to this and vowed never to go back to Google. It was a slow decay, though, where over the course of a few months I just became less and less able to log in. (Unfortunately when I could log in, I couldn't do anything to change my recovery phone number to one I actually had access to because that triggered another verification round that I could not pass because I didn't have access to the old phone number.) The best advice I can offer is to try find an old device that you once logged in from and you haven't upgraded or cleared cookies or anything. Then try to go back to the same country, city and ISP you used where it worked. Do not log in from public wifi! Make sure all your OS-level language, time zone and region settings are the exact same as they were last time you were successful too. If you are lucky you may be able to get in without a phone number and back up your data somewhere else.