not being able to ctrl-F a textbook or have click-to-chapter links sure makes studying harder these days... and any scanning software worth it's salt will at least do the bare minimum OCR automatically...
Look, it's all about authorial intent - if the author had wanted their book to be easy to reference or accessible to people who use screen readers, they would have published a DRM free PDF in the first place. Gotta respect the artist's vision.