So what's the sense of it all?

Perhaps too straightforward question (I know it's too general) but still - when there's the enlightenment why we even exists? If Samsara can be brutal and full of suffering, what's its purpose? To suffer and then enjoy how nice it is to not suffer? Or to have the choice whether to be good or bad? As humans we can surely limit the suffering. But how much really? If there are 6 realms (hell, afflicted spirit, animal, human, asura, and heavenly beings) - what sort of principles could ever decide for such an order? Isn't everything supposed to be going towards the enlightenment? If that is so - what's the sense of having e.g. the hell? To "punish" those who act as evil so they could "taste" their own acting? I'm not really sure if I understand the purpose of going through all of it.. I believe it was Erwin Schroedinger who expressed an interesting idea that the total number of all minds in the universe is one. Just one mind. Split into different lives in different time and space. If that's the case I only wonder why would the same mind ever "start" this. Most likely it's only my limited point of view. Seems like never-ending fight between good and evil. Does the Buddhism somehow grasp such let's say - more (perhaps too much) general questions?