> In my experience (it is already the case with gmail and outlook up and now), this means I will not be able to login to my account when in holiday in another c

> In my experience (it is already the case with gmail and outlook up and now), this means I will not be able to login to my account when in holiday in another city, country, or when I use a borrowed device, or when I am behind VPN/Tor, etc, unless I give google my phone number, and can afford to get a call / sms at that point of time and unblock the account. That's exactly it, there's already two Gmail accounts from high school I can't access despite knowing the passwords.