The book example is not very helpful for a few reasons. Firstly, the authors of books do get paid—writing books is not a pure tax imposed by academia. Secondl

The book example is not very helpful for a few reasons. Firstly, the authors of books do get paid—writing books is not a pure tax imposed by academia. Secondly, books are not typically at the frontier of scientific knowledge (these days). They're interesting and helpful, but accessing them is not a necessity for keeping up to date. Put simply, books do not have a monopoly on knowledge. Finally, and most importantly, books are not funded by the public. Research is. If the public is paying for something, they should have access to it.