Thing is.. I suspect that it's Not Just Twitter that's playing silly buggers with the advertising industry.
As far as I know, nearly the entire internet economy, with few exceptions, is based upon the idea that the number of viewers of advertisements reported by the likes of Google, Meta, and so on has some basis in reality. In the end, some provider of goods and/or services is paying Real Money to shove their advertisements in the face of Real People who will, presumably, be swayed and pay Real Money for those goods and/or services.
The problem is that the likes of Google, Meta, Twitter, and all have every reason to exaggerate the number of live bodies seeing those ads. The more live bodies that are out there, the more they can charge to carry those ads. Supposedly, audits by independent agencies can verify those numbers.. but there seems to be real questions as to how real those numbers are, at least with Twitter, anyway.
And this isn't a new problem by any means. Nielsen ratings, back in the day, were supposed to indicate how many viewers were watching television sets. The advent of VCRs, mute buttons, and fast channel surfing made those ratings very problematical; over the decades, I think I've seen multiple articles about how unreliable the Nielsen ratings had become.
It's gotten so bad.. that many TV set manufacturers are attempting to view actual people to see if they're there and to determine what they're watching, then selling that data to the advertising industry. Invasion of privacy, indeed: Do they have a special category for when people are screwing on the couch? Or not doing it in the proper missionary style, for sale to religious bigots everywhere?
It all feels rather like a house of cards, liable to fall over at any moment.