When I bought books in Japan, I always got my books wrapped in a piece of paper.
In subway or public places like coffee shops, it is common to see people reading books that are wrapped in a cover. I always wondered why!?
I later learned that some people don’t want their books to get damaged, and some like to have privacy regarding what they read. Some also do not want to show off when they read books in English or read about something “intelligent”.
Anyhow, don’t judge my dog book cover wearing glasses 😉