"I mean if something doesn't ever work in real life then its not good."

Are you talking about Agile, Waterfall, or project management in general?

I've seen Agile work just fine. I've also seen it fail miserably. I've seen both of these at the same company with the main difference being how aggressive/delusional the leadership is. The easy test is if your leadership is legitimately ok with your team going home early if you complete your sprint commitment early, and it actually happens on occasion.