Our aesthetic and moral models in our brains define what we consider to be a "cancer" soo.. What does that even mean. I'm pro keeping the world beautiful and rich and fulfilling to human thriving, but I also feel as an objective part of life that if we all just die and a new cycle starts then it is what it is. Life just started making oxygen and killed almost every organism alive once so it's kind of just a thing that can happen I guess. We'll see if we're capable of stopping it from happening again.
We learned by watching nature.
It's not an inevitable thing though, we could do so much better. The source of our behaviour doesn't have to dictate our control over ourselves.
We are a force in the universe trying to reduce entropy by assimilating matter and structuring it.
But ultimately life at large will be a failed experiment if the entire universe reaches a thermodynamic equilibrium where entropy is maximized.