Assuming that reading a physical book/printed magazine is inherently better than using your phone in the same situation is just a kind of snobbiness.
Someone in those photos could have been watching a veritasium video, or studying their college notes on their phone. Someone in the earlier years with a book could have been reading Mills and Boone.
But either way, who cares? Why are we judging what people do to pass a few minutes of their day in an inherently boring place like the subway?
As to the value of boredom, sure. But environment matters too. I think there's very little value to boredom on a subway. If you want to make a personal choice to be bored on the subway, go for it. But I don't see any valid reason to judge other people for choosing otherwise.
As for reading a book or a magazine - this only works for the most common topics. The internet brought up significantly more interesting things - can you remeber any printed publication that was as good as danluu's essays for example?