Not everything though. There are some books I've only ever found through antiquarian shops and private libraries (eg http://londonlibrary.co.uk/ ) which are of historical and cultural value but which will probably never be digitised. Unless I do it, anyway.

There's also a whole world of professional texts in law and other subjects which I've had to access by taking the £200 train down to London to physically sit in the British Library and read (and often, photograph). The more interesting the thing you're doing, the more likely it is that you'll need to venture to an actual library, often one of considerable age.

That's not even to mention the historical archives etc, indexes of which are held centrally but the materials are scattered all over.