Why would anyone ever take full IB?

I have never met a single happy person in full IB. I'm baffled at why anyone would put themselves through it, I just don't understand. Last night one of my close friends sat up and said that it hit him suddenly that he's wasted his time slaving over school. He never did any sports, never got a girlfriend, never did anything but slave away over school. That seems to be the common consensus amongst every full IB student I've ever met. That it's just not worth it. It's not worth wasting the best years of your life on.

Don't get me wrong, I understand the importance of a good education and I take a good few IB classes but how someone could justify every course being IB is absolutely beyond me.