But fundamentally, you've missed a pretty big step. What if god just…didn't create a situation where children get diseases that can only be cured with one rare tree?

Or, more importantly, what about diseases that cannot be cured? What about natural disasters? Yes, some types of natural disasters have gotten more common and worse as a result of human action, but they still happened before climate change, and if anything were more disruptive to people before we had modern building practices.

We're talking about a god that is literally capable of anything. It could just wave its hand and delete all disease from existence. It chooses not to.