Audiobookbay is very popular and https://rargb.to/ apparently caters to e-books. I found those just by googling. Between VPNs and bit torrent, there’s not a whole lot I guess you can’t get.
Also, consider that a reading habit is affordable to most of us, but not to everyone in the world. Books, specially educational books, shouldn't be a luxury.
https://news.ycombinator.com/item?id=33460970