Nah, just create the world at a state where modern medicine can cure cancer, like we're on the slow road to doing.
In the 1800s someone might have asked "if suffering is required and a child is going to die of a systemic infection, maybe the whole project should have been scrapped at the planning phase".
To me it's clear that human flourishing without much suffering is possible in this universe and it's more about knowledge and power to prevent suffering being hard to come by. The kind of knowledge that e.g. could have been written down in ancient religious books or whatever if we had a best possible world.
> Nah, just create the world at a state where modern medicine can cure cancer, like we're on the slow road to doing.
We would have cures for every illness if not for human selfishness and evil. Look at all the money and effort spent on war during the last 10,000 years, on legal fees and disputes for the last 5,000 years. Rather than love our neighbors as ourselves, too many of us in our hearts say, "This land is MINE! This money is MINE! This patent is MINE! The credit is MINE!" If all this effort went to instead cultivating gifted individuals to research and cure diseases we'd have all our cures.