It's not that nothing compares, but rather that the two are too different to compare.
Books improve if you have more imagination, but require you to actively make up the world in your mind for maximum effect.
On the other hand anime force-feeds everything to you. Characters, movements, sound, scenery, etc. It's much less involved, you're not imagining, only watching. There are also a fair few cases where the saying "a picture is worth a thousand words" comes into play - some concepts are just executed better when seen, not read.
They're two completely different types of entertainment.