Film v Print

I think that the major difference between movies and books are that when you are reading a book, you will have to imagine the scenes, but if you are watching a movie, the scenes will be in front of you. So, when you are reading a book, you will use a lot of imagination, but when you are watching a movie, other people did the thinking for you already. A book can show what the person is thinking about, or some detailed actions that even if the movie has it, the audience may not notice. A movie can show us how the scenes and the characters look like. Most people now like to watch movies, including me too, but there are actually bad things about watching movies. First of all, it hurts our eyes, even though books do hurt eyes too, reading books won't be that "poisonous". Second of all, it lowers people's imagination. When people are reading books, they will have to imagine how the characters look like, what scenes there are...etc. But when people are watching a movie, the movie shows the people everything. Third of all, filming a movie is a big waste of money and resources. A movie can cost A LOT to film it. Why don't people just read books?
PS: I know it's kind of off topic, but I don't know what to write about.