Of the many things Ray Bradbury wrote that seemed most prophetic about our (horrible) moment in time, Fahrenheit 451 is not the one that comes most to mind for me. It's a short story named "The Murderer", written in 1950-something. Go look it up if you don't know it.
The story involves a man who lives in a time where everyone has two-way wrist radios (their version of a smartphone), and where they are used in much the same way people use Twitter or Facebook today — to brag, to bombard their friends incessantly with noise and useless chatter, and so on. The protagonist rebels against the destruction of his attention span by smashing the device. He is rejected as a neurotic who can't adapt to the world, but it's clearly the rest of us who distract ourselves every 20 seconds who are the really crazy ones.
Again: This story was written in 1950-something.
I read that story when I was a kid and never completely forgot it. What strikes me about it now is not that it was technologically accurate, because if you wait long enough someone's likely to invent most anything that can be imagined. It was the sociological accuracy — that once you put instant real-time communications in the hands of the masses, you don't get a society that becomes all the more empathic or enlightened because it is now that much more aware of its fellow man. You get bragging and one-upsmanship and tribalism. You get the trivialization of knowledge, wisdom, and experience.
And even those who reject it aren't able to benefit anyone except their sweet selves by way of their act of rejection. They aren't able to get the rest of the world to follow along by dint of their act of resistance; they're merely trying to preserve what personal dignity they can extract from a bad situation. I find it notable that the end of the story is about how the "murderer"'s rebellion is not admired or even found disturbing, but just shrugged off. One more loony for the loony bin.
I'm not going to go so far out on a limb as to suggest that the whole mess we're in now is the fault of social media or smartphone tech. I do think it was made a whole lot easier, though. Social media in particular I blame for achieving this all in the name of conveniences that turned out to be nothing more than cheap dopamine rewards with no long-term benefit.