Where are all the books?

I’m writing this on the commute home where on multiple cars ridden by hundreds of people I spot exactly one physical book. Everyone else is staring at their smartphone, tablet or, like me, their computer. There isn’t even a newspaper to be found. When I first started riding the train in the late 1980s, you could barely hear yourself think over the rustling of newsprint. 

The problem is not, obviously, with books themselves. People are still reading. It's the platform I question.