I don't think people mind sequels so much and encouraging users to consume more content goes back to simple cliff hangers in comic strips serialised in newspapers back in the early 20th century. I don't think anyone would have classified such techniques as "ads", at the time so I am a little surprised by such classification.

I think product placement is particularly rife and problematic, today in a reasonably new form especially since it bleeds into the culture of social influencers and in many nations is not regulated to enforce disclosure.

However, I think you might struggle to make a case that "today's audiences" are any more susceptible to advertising than any other audience throughout history. I would suggest (and personally believe) that the idea of "ick, ads" is our own personal niche that moves us away from the centre of the bell curve. Many people don't appear to respect the harm adverts do to the mind, or perhaps I am one of the few that overstates their detriment, depending on one's perspective.