Depends on the kind of book. I 100% want physical copies when it comes to art books/illustration books, there's literally no point in buying them if it was digital. I don't read many fiction books much, but when I do it's always a physical copy. Imo reading is supposed to be an activity to take a break from technology.
Textbooks, language books and most learning books though, I definitely prefer these digitally especially since my notes are written digitally on an ipad. It's easier to scroll through and make connections with my own notes, as I can easily screenshot bits of information to put in my own notebook, and scribble all over it.