What I don’t understand about policy violations is why Google never warns the user before banning. A simple alert or email would reduce so much frustration on the part of users and so much overhead for Google.

ToS change frequently and it’s not really fair to assume the user knows what is and is not correct use of tokens.

Not just Google. This seems to be the default for most tech giants. I was banned on Facebook for an unknown reason, not provided any explanation, and given zero recourse. Had to resort to reaching out to a friend who worked there.