Are my girlfriend and I just meant to be friends?

Yes she might be everything perfect for you on paper and what you would generally like out of a girl but by the sounds of it it's missing that something more, the something more that can't be just gained, it's usually there or not. By the sounds of it you might be lacking that feeling of attraction and chemistry, while physical and attraction isn't everything but it's a massive part in the long term relationships and it can break a relationship down. If this isn't there I would consider breaking up because it is important and it will only get worse over time. Sex and attraction parts usually dwindle over time but if it hasn't even initially been there that's not a good sign.