Those buying baked in ads just need to find other ways to verify value. This is nothing new, no large company buys ads without checking how they really work (though many small companies would). There is someone who checks all those "how did you hear about us" responses asked at checkout - they want to know if the ad really provided value. Sure the TV stations tracked and reported ratings, but that is only one of the signs ad buyers look at, and it is one they only trust because they check and so would catch if it is manipulated.

The ad business is far older than the internet and there is a lot of old knowledge that apples directly to the internet. Those buying backed in ads should be aware of and tracking such efforts.

A lot of sponsors have shyed away from YouTube because of the fake views and botting problem.

Some were paying big money to streamers with 20,000 live viewers. Even though 19000 of those were fake.

The sponsor then sees the ad and did terribly and doesn't sponsor anyone else in the future.