I lost a lot of accounts because of this misunderstanding. I always use a VPN for work. I keep all logins and passwords in the password manager. But Google is very worried about my safety, even to my detriment.
If anyone wants to see how intent big tech is on tying your profiles back to personally identifiable information, connect to a VPN and try to create new accounts on various services. It's basically impossible without a non-VOIP phone number. If you manage to get an email address, big sites like Facebook and Twitter will instantly lock your account and require SMS verification.
Big tech discriminates against anyone that doesn't have enough money to own a phone.
My general understanding is that Google wants to prevent account takeovers, as it happens far too often. They flag accounts for various heuristics, even if you know the login (as it could be someone that stole your credentials). This normally should just trigger 2FA for that login. If that doesn't work, you likely need to go through the account recovery flow:
I hope they appoint the fruit ninja as head of the DoJ so he can slice Google into a thousand pieces :-)
Every one of them required a phone number and had all kinds of algos and databases in place to thwart anonymity. If all of your demographic information didn't match the country your IP address was in the experience turned into a brick wall.
I did this a few years ago when establishing an onion (new accounts created and accessed only over VPN+TOR) identity for the dark web and didn't have a problem.
If I needed to hide my identity and communicate with people as a non-techie journalist or dissident I would not know how to proceed at this point.
This is not being done to fight terrorism. The real reason is to ensure that every user is a real person that can be sold.
When some fat cat spend thrift advertising executive complains about possible sock puppets numbering in the millions on their platform they just kick back and explain thier byzantine system of identity verification.