I feel need is better than want, for both to not just want but need each other, their hearts depending on each other. Otherwise, it is like going to bed with socks on! Wanting but not needing is like holding something back emotionally out of fear of being vulnerable, which prevents total intimacy happening. The downside is that if you grow to need someone and then either of you has to call it off, then it is going to hurt for both of you. But if you can't stand the heat, stay out of the kitchen!
The baby needs the mother for food and protection. Hopefully an adult is not going to need their partner like that, but still their hearts grow to depend on each other. I've had experience of needing different partner in different ways, physically, emotionally, or for the way she opens up social opportunities or perhaps I need her house, car, whatever. A couple of times, I've fallen apart a bit when relationships broke up and other times had my life opportunities grind to a halt as I had to see out new social circles. Thankfully, in the longer term, I've healed and life has gone on. But in the short term, each break-up felt as if my water supply had been cut off, something I needed was not available.
Having said that, there is neediness, which is something else again and not healthy or attractive. A feeling of wet cement pulling you down, unrealistic expectations and demands being piled on one partner by another.
One thing I feel about threads like this sometimes disagreements are semantic rather than actually disagreeing. Like using the same word in different ways...