More about that hypothesis in a book by Voltaire, which explains why according to a theory of Leibniz everything will actually be just fine.

We don't need to worry about catastrophic risk. What if everything goes right, instead? Leibniz says it should, in fact it couldn't possibly go any better.

As the saying goes, the optimist believes we live in the best of all possible worlds. The pessimist fears that this is true.