It's only going to get waaay worse. I think it's all a symptom of fear. Fear of feeling stupid, fear of getting left behind by an increasingly complex world. How better to fight complexity than to simply reject it?
There is so much information out there, and more and more every day. People begin to feel overwhelmed - "Experts say I should eat eggs.", then "Eggs will kill me, what??". Combine information overload with mass media stoking and profiting on fear, and it makes sense people will start to just "check out".
It starts small, an act of personal anti-intellectual rebellion against the system that always seems to know more than you, and is always telling you how wrong you are. Maybe you think aliens built the pyramids. Maybe vaccines cause autism. Maybe Jews control the media. And suddenly, instead of just everyone telling you you're a bigoted, ignorant, WRONG person, there are all these groups of like minded people telling you, "They told us we were wrong too! But we know the secret TRUTH, and now SO DO YOU", Enabled and invigorated by your new friends and shielded from the onslaught of the modern world (and having to
think about things! Ew!), most people will just go deeper and deeper, and insulate themselves more and more from rationality. Who's stupid now!? (Spoiler: yep, still you)
So we start with climate science denial, and end up at GRAVITY denial. Politically, all facts are all just "spin" anyway, so why listen to anything that doesn't reaffirm your own biases? We crossed the bipartisan event horizon some time ago and barely noticed the turbulence. Used to be a Holocaust denier would be a social pariah, now they work out of the White House.
So where do we go? Well, maybe it's just the growing pains of the information age. The industrial revolution spawned factory-smashing Luddites - maybe flat-earthers are just throwing their wrenches into the gears of science. Look how that worked out for the Luddites.
Or maybe this is just how it's going to be forever. Information and complexity aren't going away, quite the opposite. Maybe the only way we catch up is by maintaining an educated populace, with critical thinking skills for the modern world. How are public schools doing btw?
Oh.