You couldn't actually do stuff to the main characters that really fucked them up. I remember reading the Six-Billion-Dollar Bastard battle and I was was so pissed off. But in a good way. It was just odd seeing th entire team get their ass handed to them. But under DC you have to maintain the Status Quo and that is Superman beat everybody, Batman is God, and Wonder Woman is only badass when she's out of the panel or if you need to remember oh yeah, women do stuff too!
The Authority doesn't really work in a world where the good guys win, not because they're supposed to, but because they're really good people trying to do their best!
The world where the Authority comes from, lets them exist in a way that says, sure they're bad but it's not like they're the worst.