A lot of the material I checked out on IA was older books still in copyright, but no longer published. And physical copies get warn over time. Existing knowledge should remain accessible. Publishers do not act in the best interest of authors, they squeeze higher percentages from them just like any other content distribution platform.
If IA had fought that fight ... dealing with copyright holders who have stopped publishing and made this content unavailable, they would have had more support at every step of the way.