Why not link instead to the article this article links to and is based on, which is far more informative:
Troll farms reached 140 million Americans a month on Facebook before 2020 election, internal report shows
https://www.technologyreview.com/2021/09/16/1035851/facebook...
I can see nearly half of all Americans regularly engaging with SOME Facebook property, if you include Instagram and WhatsApp, etc. But the original old Facebook itself? In the 2020’s? I don’t know a single person who still uses that.
I am responding to a quote claiming that troll fake news "reached 140 million on Facebook". Clearly, this is speaking to the latter.
You would have to be a fairly active user to run across deliberate misinformation, generated by offshore troll farms. That's not "I login once in a blue moon to spy on my ex", or "I have Messenger on my phone because a group that I'm in uses it to announce events". That is "I actively choose to consume angry and dumb political content on a regular basis". Perhaps I overestimate people, but 140 million seems high.
I think you are missing the point of this research. The entire point is that 19 of the top 20 Christian pages, for example, are produced by offshore troll farms, and until recently, this was generally not known.
So no, you do not need to be a fairly active user, not at all. Many, many casual users came across this because it was incredibly widely shared, and because Facebook's algorithms push such content far and wide.
That's my take, too. I know exactly the sort of mass-produced garbage content they're talking about, since I see things that my friends interacted with in my Feed. Therefore I am part of the 140 million people who was exposed to the media produced by these operations.
7/10 Americans are Christian[1]
So, there are around 210M American Christians on FB.
So, these posts reached roughly 60% of Christians. Sounds feasible to me. Top brands in a niche like Christians can get broad reach.
[0] https://www.statista.com/statistics/408971/number-of-us-face...
[1] https://en.m.wikipedia.org/wiki/Christianity_in_the_United_S...