Take the United Kingdom. Google says Foo Ltd. are the advertiser, who are Foo Ltd? Well the UK legally requires Foo Ltd. to register with Companies House, a government agency, and this registration legally must identify Persons with Significant Control, actual humans who make decisions for Foo Ltd.
But when you look closer you discover that Foo Ltd has a company secretary who lives in a run down area of an ex-industrial city, and who is listed as secretary for 1800 other companies, and its offices are registered as that person's flat. The PSC section is filled out with the name Offshore Holdings Inc. offering the address of a law firm in the British Virgin Islands, even though the law is clear that Persons means very specifically human individuals.
The UK could clean this up, but of course the people hidden behind this sort of thing are actually wealthy and powerful and are doing all they can to ensure nothing changes. Similar things happen in the US, and in several other developed nations you probably think of as law-abiding and straight dealing. Google can't fix any of that, so this is all you get.