What's the point of a girlfriend?

What is the point of dating? What is the point of relationships? I've been asking myself this a lot recently. Because, honestly, I want a girlfriend. Or, at least, I think I do. I definitely want a relationship like the one I have been imagining. But, is it really dating? ... I don't know. Here, let me explain.
I think the thing I have always longed for is someone that I can care for; someone that trusts me completely, that comes to me when she has issues, that lets me care for her... Does that sound good? Someone to hug and comfort, and enjoy... Sounds great, right?
But, is something missing? Read it back, think about it. I'll wait. ... ... ... Do you see it? All it is is me pouring in to her, me giving to her, but no return. She is not giving anything to me, and I am not asking for anything. I am not expecting her to give much in this relationship. And that's wrong. There is no way that that can be right. Even if she is great, and funny, and likes to travel and likes board games, if she doesn't give back to me, than I really don't think the relationship will go to far.
So, my question is - where did I get this picture? Where did this idea come from? Well, I think it comes from the picture of masculinity that society portrays - it is the man's job to do everything to care for his girl, who in return lets him take care of her and has sex with him. And the problem is that a lot of guys are fine with this, for a while. But eventually they get tired of it, or their girl does, and sooner or later someone breaks it off. I really think this is a big part of the reason that there is so much divorce. Guys are never taught they need to take from their wives just as they need to give. They do not have to deal with everything themselves; in fact, they shouldn't. That is why they married their beloved girl - they are agreeing to work through things together, and to take care of each other.
I think that to know if a girl you would consider dating will give back to you you have to be friends first.
So, in my case at least, this is plan. I am going to talk to the girl that put my mind on this to begin with, and ask if it's okay for us to just be friends for now, until we can really be friends first. I'll let you know how it goes.