I have (had?) a Google account tied to my email (which is on a domain I own). Not sure if I ever gave them my phone number, initially. Tried to login a few years back, correct password, but they insisted on me entering my phone. Finally I did - and they can't let me in because my "provider is not supported" and they can't send an SMS with the code, so I'm locked out. Tried every few months since then, no go. Fortunately I didn't lose much (except some family photos), but it is annoying as hell. I wouldn't trust Google with anything important. And yes, I tried with an brand new number on a new phone, unrelated provider. No dice. According to reddit I'm far from alone in this. So if you rely on a Google account for anything... Well, good luck!

Google services are best treated as a liability.

Make Google Takeouts a part of your backup routine.