No, there are literally millions of books that have not been digitized and placed on the web. You severely underestimate the number of books that have been published. First, many old books are not available to the public. Second, many contain controlled intellectual property and are never provided in digital form in order to protect the content. Third, many are considered obsolete and of little interest to the masses. Fourth, some are prohibited from being copied to electronic media in order to maintain a royalty flow through physical purchase.
I use a great deal of material that is not available on the web. It is necessary to comb through sources of rare books or cough up hard cash for print-on-demand volumes.