Religion

to work out the randomness of it all, I guess. If there's no universal reason for existence, then many people can't think of anything to do, I guess.

Over the generations, humans have figured out what works for getting along with others and ideas like reciprocity, which gives everyone a reason to treat others well. I mean treating others as you'd like to be treated just makes simple logical sense. There's no need for some overriding creator to come up with that, or any of the other basic social ethics.

But, some don't want to be bothered with hard things like logical thinking, and prefer to have the rules cast in stone, or carved in stone, by some entity. So, we came up with gods and religions to handle all that and to give us simple explanations for complicated things.

It's all unnecessary. Society and culture can teach all that stuff without any rules supposedly imposed by some invisible entity. We learn by reasoning, experience, and history, and can pass what has been learned on to others. Simple.

The "God shortcut" isn't really a shortcut at all. It just complicates a simple thing.