Spammers can create a new identity relatively cheaply, resetting their trustworthiness score. Google surely already buckets advertiser based on trustworthiness internally.
Google and all the tech companies need to be held to account for this shit. Facebook in 2024 estimated as much as 10% of their revenue, $16 billion, would come from scams and ads that should be banned on their platform, and everyone suffers for it. I call bullshit on the notion that they can't afford to do better because scale. Spend some of those billions of dollars on human review. Spend some of those billions of dollars remunerating the people who get scammed through your platform. If you can't afford to keep running your advertising business after that, then it gets shut down, there's no inherent right to the monopoly on advertising that Google has had for over a decade.
Stop making excuses for companies worth trillions of dollars.
Of course, this will cost money, both because it will cost them legitimate customers that get caught up in the friction and because implementing the measures/reviews has costs, so they will only do it if forced. If they can just externalize the cost (in the form of scam victims getting hurt by scams) and/or can profit from the scams without sufficient downsides, they're going to do just that...
They just care whether the check clears.
But this is not how actual FICO scores work, and more interestingly, also not how historically Google has assigned domain authority for PageRank.
In both cases a history of transactions is required. Even if you could just spin up a new ID for a FICO score, having zero or little credit history typically means you'll have a very hard time securing any meaningful loans. Likewise, in the days when PageRank mattered a new domain would typically take a year to build up the authority required to get good results ranking well. Of course there were work around, but there are plenty of examples where easy to create a new identity does not equate starting with a fresh reputation (in fact even HN has the same principle! New accounts cannot, for example, downvote)