Hell the idea that they can even 'control the attention' is a fallacy that assumes they have active knowledge of what their content will do like the New York Times has an editorial control. It is like the idiot congresspeople who spent their question time complaining about their negative search results for their name.
Even the heaviest handed management would fail to exercise the level of control as an editor of a scientific journal who knows absolutely nothing about the underlying field.
A few big corporate tech players are increasingly growing in power to influence/control collective behaviour. Which includes funding internal departments to lobby to change laws based on some agenda. Those laws control human behaviour. Those tech organisations also determine the information flow of: words, symbols, images, effectively culture. There is a reason why militaries invest money in meme warfare for example, and these organisation effectively have that power.
It turned out to be a powerful idea. Technology is also developing faster now than ever before. To what extent they're related may be up to debate, but at least according to Harari, there's a very virtuous cycle between science and capital (also empire, but that's a separate topic).