I once used Google’s account recovery flow on an old dormant (for maybe three years?) account. Did everything asked and reached a state where they wouldn’t ask me to do anything else to demonstrate ownership but I’m still suspicious or something like that. Fortunately I had nothing important there. Pro tip: operate as if Google doesn’t have a recovery flow at all.

This is not true for Google at least. I have been locked out of a secondary google account because they thought it was suspicious that I logged in from a new IP address after 6 months of disuse. I have the password, I have the TOTP codes, I have the recovery email (in fact I even have the email for that account, as it forwards to my primary account), but login is just not allowed until I accept a push notification on a destroyed device.

For some reason, my primary account was not subject to the same probablistic lockout, maybe because it had a more constant record of use, or maybe because it was a GApps account.