Netflix was doing promos before movies, although it seemed to stop about the same time Hulu offered a commercial free option. Maybe they realized what a bad move it was.
As for recommendations, all I ever get is suggestions for Netflix originals, and I never watch them. Last night I watched Saving Private Ryan and afterwards it suggested the new Netflix show The Little Prince. I've rated thousands of movies and it's worthless.
Netflix has run ads for Netflix exclusives before other movies, and I've argued with people who insisted they weren't ads because they're for Netflix. So you can fool some people into watching commercials.
And if CBS put all their content going all the way back to the 1950s up for commercial-free streaming, I'd say that was worth a monthly payment. But that will never happen.
That's like saying the moment we had automobiles we should have outlawed horses and buggies, when in fact they co-existed for a number of years until enough people had cars to mostly eliminate horses from roads.
If we could shut down the current system and replace it with something else, we would have had self-driving cars long ago, but you can't simply stop the world and change everything overnight.
The Olympics are on cable because at one time, people were in a cable bubble. They went where people were. If people are in a Facebook bubble then they need tobe be getting themselves over to Facebook pronto.
It's their job to put events where people will watch them, not expect people come to them. You can't blame the public for ignoring you. They're not the ones missing out - you are. The Olympics are only as important as the number of people that care.