Which is better? 2d Girls VS 3D girls?

Ok I'm confused. So many people keep saying 2D is better but how is that physically possible? I'm not dissing I'm a noob and I need someone to tell me what the hell everyone is talking about. The last time I checked you can't have with a cartoon. (Though if I could have my own Chi Believe me I would be on board!) Also a cartoon can't really respond to anything you say and there for cant really love or even converse with you. Am I way off base or are people talking about something completely different?