And the answer should never be just "sorry, we can't confirm your identity right now". If I pass every challenge Google throws at me, I should be let into the account, period. If they have more, sure, whatever, let's play the game, but if I did everything right and still can't get in, that's a broken authentication system.
If that is your argument then it is their service. They can decide how to offer it. Services like this are designed for majority - and a majority are happy. If you don't prefer then you can find alternate services. Market is wide open.
(Curious how easy it was for me to forget that it's something I can turn off, once I turned it on.)
I have a client who tries to share one Google / Gmail Inbox account between users internationally and Google does not like that at all!
Google constantly requires verification for logins!
May be you/your client needs a proper workflow. May be you need to run some security company/email service at the level of Google to see.
It's a weird problem. Can't log in to my account from unknown mobile but works just fine on an unknown PC.
So frustrating.
Good thing google has a high quality help desk to report bugs /s
Makes sense really.
Anecdotally, my Google account's password has never been in any dump (password manager, very long random alphanumeric, changes every 6 months) and I too deal with these annoying prompts.
Despite having access to the password, the recovery email account and an active session, I could not activate a new session.
It didn’t make sense, not that it matters when google refused to have a help desk or meaningful way to report bugs.