Let's concede you can't shape narrative or change peoples minds through online content (though I would disagree on this). The very act of addicting people to digital platforms is enough for control. Drain their dopamine daily, fragment them into isolated groups, use influencers as proxies for control, and voila, you have an effect.
I would agree with you. It's easier to just muddy the waters and degrade people's ability to hold attention or think critically. But that is not the same thing as convincing them of what you want them to think.
It's always easier to throw petrol on an existing fire than to light one.