A rule of thumb.
The novel has more depth than the manga.
And the manga has more depth than the anime.
But an animation has movement and sound and music. Also, manga are mostly monochrome.
So anime can give a different kind of immersion.
F.e. action scenes, slapstick jokes and certain emotions simply work better when animated.
Doubtful? Just stare at the picture in this spoiler for a while.