That’s a wrong question to ask. To see this, compare: Which needs does poetry satisfy?
Reading poetry does not satisfy any pre-existing need. Before you knew there was poetry in the world, or before you started reading it, you felt nothing missing in your life. You may have been completely happy without it – just like without classical music, or without ballet. But when you discovered poetry (or classical music, or ballet), then you discovered something new and powerfully meaningful. And now that you experienced this meaningfulness – not before! – perhaps you “need” it.
Thus, poetry did not satisfy an existing need; it CREATED a new need. Reading poetry revealed to you a new domain of higher meanings, which you never knew existed, which you never missed, but now you miss it.
Deep Philosophy is not the same as Poetry, but at this point they are similar. If you have never contemplated fundamental ideas in your inner depth, if you have never experienced the precious power of ideas resonating within you, if you were never touched by the fundamental voices of reality, then you probably don’t feel it missing in your life. Deep Philosophy does not satisfy a need that you already have. You don’t really “need” it for any existing purpose. But once you start practicing it, then you discover a new dimension of meanings that are deeper, more sublime and precious than many things you know. And only now you realize how important it can be to you, and how flat life can be without it.
Deep Philosophy opens a higher dimension of meaningfulness – of depth, of preciousness, of realness.
“Alright, so can you explain this higher meaningfulness?”
How can I? Can you explain the meaningfulness of poetry or of music? Higher dimensions of meaning cannot be described from the outside. You must enter them to appreciate them. You must practice Deep Philosophy in order to experience its realness and preciousness, and witness the new horizons of meaningfulness opening to you.