if i'm allowed to ramble on a similar but adjacent topic, there are some books i encountered which while yes ebooks of them exist on the internet i don't think the form of an ebook does their contents complete justice, because their original formatting plays a lot with how the words flow! a good-quality pdf can kind of capture the vibe but not quite (especially not when something goes from one page to another) and other formats are Right Out
for an easily-accessible-to-the-public-eye example of this:
Principia Discordia. i first encountered these amazing texts in paperback and let me tell you, flipping through that was an experience an internet version cannot even begin to replicate :D