Book are still super important. In fact not everyone can afford to buy books. Esp in large metropolitan area where there is any sort of impoverish population. They can't afford book let alone a kindle.
That neuroscience journal might not have been on the racks but I'll bet there is a good chance it was in one of the online databases that libraries pay good money to have access to. Feel free to check out the prices online and I'll bet most will pass on paying for it your self.
Also illustrated Children's Books are something even parents in Suburbia take advantage of as children go through them quickly and they are very expensive to buy.
That said many libraries hold on to books long past their relevance. And more space and time should be devoted to public events, like video games, and education, like the class my wife teaches "how to sigh up for email" and "learning to use the mouse".