Books are no different from other stuff. It's better to apply the same standards to books when you you are trying to get rid of useless stuff. And it's not only

Books are no different from other stuff. It's better to apply the same standards to books when you you are trying to get rid of useless stuff. And it's not only about paper books (it's obvious they have huge downsides, because they are heavy). Electronic books are also should be deleted if they are not useful anymore. Our attention span is very limited, and new information tends to have better quality than old information (on average).