OK here's my Anarchist "Hot take". It's not correct, but I'm building an oversimplified model to make what's happening somewhat visible. Let's divide people up into two groups: One group has "experts", who are pretty alone / introverted, but doesn't really do the work of meeting up with others. The other group has people who know how to gather a party together, through a bbq or cookout or family meals or an actual party, but aren't too bright.

In the past, both groups were kind of homogenised together, to the extent that neither group really knew the existence of the other, but they knew how to make things "work". Like the experts didn't know how the cookouts happened, but they just needed to turn up, and enjoy the party. The rest was more or less magic. The other group knew the effort to bring people together, but didn't realise that some of those people were more valuable than the others. The actual dissemination of expertise was more or less magic.

Today, we have social media. The cookouts happen in social-media spaces, but what's happened is that the experts and the non-experts have split (sort of like the milk we're talking about here). The experts can "meet" without the party people, and the party people "meet" with the other party people. In the past, the experts would naturally become the trusted members of society because people would know them over the years being right over and over. Today, however, the experts are effectively in a different world to the party people, who are all vying for a "trusted position". This is valuable, because the party people are "gullible" -- I don't mean this in a negative sense, just that they must trust the expertise around them, the social proof, or the consensus. Repeating that this used to work because actual experts used to be among them.

So you have people like Alex Jones, who is a snake oil salesman. In the past, a niece or nephew might have been able to tell their family not to listen to Alex Jones, and that would have worked. However, that's no longer effective because Jones has unadulterated, prime position straight to the party people's brain sockets through talking for hours at end about this crazy stuff. The nephew is also not at enough of the cookouts to counteract that. This pushes the family apart (we've seen this narrative now, people who are so far in the alt-right pipeline they can't back out) and allows Jones and co to completely wreck these people's lives.

So in short, I don't think this is a consensus reality thing. I think it's a filter bubble thing. We've managed to make it easy enough to filter things we don't want to hear, and to not work with people who don't agree with us. Oh and don't think the "experts" are in a better position here. They fundamentally can't organise a party. They don't know how.