Dead wrong.
They are lined with books that only serious students read.
Not only is everything not on the net, contrary to widespread assertions internet information isnt anything close to “forever” - its “until the servers need upgrading”.
The degree to which the campus library is used is a direct, accurate, and visible corollary to how much serious study is going on.
Library’s are warehouses for out of print books and papers. They should toss the books into Yucca mountain for people to find 100,000 years from now. Students only use the stacks to hide from prying eyes.