macOS wants to access your Google Account

I'm not sure what your question is.

The reason MacOS is asking for access to your Google account is usually because you have Gmail connected to your Apple Mail app and it is simply asking you for permission to finish configuring it properly. There is nothing nefarious here.

If you don't want that, open up your "Accounts" option in Apple Mail, and delete your Gmail account and move on. No need for the political statement.

You are misunderstanding this. Your mac is not trying to use your account "behind your back".

This is a normal alert to confirm that you want to use your account on this mac, or not.

Nothing out of the ordinary in today's era of increased security, where you are often asked to confirm that is you who are doing stuff, like with two-factor authentication.

I am not quite sure exactly what you are referring to (except your quote from Apple); however:

I would not allow Google anything anywhere near any of my Macs. I do not care to do business with companies whose sole source of income is the sale of your information. If you don't mind them using you to further their bottom line, go ahead and allow them to do whatever. And, you are controlling what Google gets to do with your info via the mac OS.

My humble opinion: I find that to be a good thing. And, I do not allow Facebook either as their aim is much the same as Google's.