This is just a sad consequence of some merchants creating accounts in the thousands/hundreds of thousands and selling them to SEO/Marketing blackhats to use.
Google should simply have paid, in-person support for these issues. Cuts off the spam merchants, while still letting Joe Average create an account with their usual phone number once they've been verified as an actual person. That's got to have some value, even to Google themselves.
I don't think that would go over well. When Google asked people to share a national ID or credit card in the EU (age verification is legally required to be compliant with the new "think of the children" regulations in the EU's Audiovisual Media Services Directive), people online freaked out.