> people just no longer critically process information, and move on to the next thing
Sadly I don't even think this is true. I think "people" in general have always been like this, and social media hasn't really changed that. You mentioned the barrier to entry dropping to zero. I think most of these issues are almost solely a result of that. The intellectual bias that used to be present in "the discourse" has been erased. The politicians/CEOs no longer have doubts, there's no reason to hedge. They know exactly how easy it is to manipulate the populace.
I think both are really interlocked. Low barrier of entry = a flood of info = low attention spans as a defense mechanism to deal with it.
Even if you're paying attention you can't keep it all straight in your head. You have to be a real time BS processing machine these days. And that simply isn't possible.
In the past, one had to be published in a magazine, a paper, or show up on TV - not an easy task, just to say something.
Then we had blogs, which was a vast improvement in giving people voice, but at the same time a very good center ground. Setting up a blog, and then writing an entry is not that enjoyable. You need to really have something to say to go cross that bridge.
Now, however, you just open up your app and go "LOLZ LOLZ STUPID LIBS R SO TRIGGERED MAGA". Done.
Social media is where social conscience goes to die, so yes, I believe it.
There is a very good reason why the tornado of lies we hear from the VERY top of our government, and in fact, governments, is because social media brought down the attention span to zero. It's not that they became better liars - people just no longer critically process information, and move on to the next thing.