Why didn't we end human life earlier?

Well, think about it. Humans are just energy that cannot be destroyed or recreated, just changed. We're the same as trees, rocks and nuclear missiles, which are also energies. Our feelings are just energies, and our pain is just indicated by our nerve cells that say that something is wrong.

Now, doesn't everyone want people to live and to prosper? Who seriously enjoys watching people in Africa starve to death? Clearly very few people. But we still multiply, and soon, hundreds of billions of people could live in the world, most likely even in space. Now, researchers have said that the universe WILL come to an end at some point, most likely by a collapse and merge of everything back into one single point. By then, nothing can or will be remembered.

So, if we're all destined to die and be forgotten anyway, why don't we end all human life right away? Six billion people would suffer far less than several hundreds of billions, so aren't we in fact just planning to torture humanity by living on this planet?