The way people get (mis)information has been changing constantly, and a constant during all of that has also been people decrying the fact that people are going to get bad information from some new scary sources. HOW DO YOU KNOW WHO IS WRITING A BLOG AND IF WHAT YOU ARE READING THERE IS CORRECT the journalist thundered from his desk at Fox News.
You don't need facebook for propaganda and you don't Russian twitter bots, either. The focus on Russian influence has let everybody else off the hook. Any time there's some bullshit on the internet people scream "RUSSIA!" Yah, well, maybe it is, but while that's an issue it isn't the sole source of bullshit on the internet. You don't need rubles for that. We have a very well funded domestic conservative bullshit operation.
It is scary that your MAGA-brains share every piece of bullshit from any website on facebook. Email forwards from the old days from your racist uncle were scary, too. As is Rush Limbaugh, Fox News, bulk mail propaganda, etc. I'm not saying all of these are precisely the same thing, but hoping for some referees, or even the Marshal of the Supreme Court, to somehow correct for them, is not going to be productive. There are no referees.
To the extent that something like Facebook is a uniquely bad feature in the year of our Gritty, 2019, you have to fix them with power. Your personal power, political power, etc. Appealing to Zuck to do the right thing is silly. And, really, while it's reasonable to ask all of these entities to enforce the rules they claim they enforce, otherwise they're going to do what they're going to do as long as it makes them money. I don't really understand what motivates these rich weirdos, but apparently "doing good" is not it.