story
Manufacturing consent in this context would require the gradual but systematic elimination of every major platform and medium that might publish narratives contrary to the desired one, and that's simply not possible. And even if it were, that clearly artificial homogeneity would itself drive distrust. See the USSR where the government not only directly controlled literally every single medium for communication, but also strictly ideologically filtered for admittance (or exit) from the country. Nonetheless this led to widespread jokes like, "Why do we have two newspapers, Pravda (meaning truth) and Novesti (meaning news)? Well that's because there's no news in the truth, and no truth in the news."
So we can even go one step further and say that to manufacture consent you need to not only eliminate all dissenting views, but you also need to somehow hide that from your public and make them believe that what they are reading is free to diverge from the official narrative. Chomsky, of course, hit on this exact nuance with his famous quote, "The smart way to keep people passive and obedient is to strictly limit the spectrum of acceptable opinion, but allow very lively debate within that spectrum..." But now a days you can no longer limit the spectrum of acceptable opinion, because with the internet you can find communities where basically any view, no matter how fringe, is the norm.