> What's the tangible financial impact to someone who's been deemed undesirable by Google?

Depends how deep you got. I for one would lose access to my mobile phone (Google Fi) and email, so it would be very hard for me to get access to anything that uses my phone number for 2FA. Or the email address for any kind of account recovery. Huge nuisance but maybe no financial consequences, except maybe an involuntary trip to the bank's branch to access the account.