Strive1154 If all else fails, what am I really giving up by providing my actual phone number?
Like everyone else, they just use it to slow down the abusive activity. I'd be surprised to learn that their approach differs much from what more privacy-respecting organizations do. Their messaging at least implies just that. I really don't think they store it in plain text.
In any case, the last time I checked, if you later decide to set up 2FA for your Google Account, they will first ask you to add a number anyway before setting up TOTP or hardware key. I think you're okay. Personally, if they disable my throwaway account I'd be okay using my regular Google Account on GOS. I wouldn't lose any sleep over it. YMMV.