Great post… and good code. A helper library for reducing redux boilerplate, by providing a different way to write it.
But, I am still thinking you underestimated React’s setState power. Your example shows the object variant of it, not the functional one. Which IMHO is really more useful (and is ready to be even more with Fiber)
Since you can write functional versions of setState, those functions can be abstracted, composed, “diced and baked” in a lot of functional ways. You can practically have the same redux approach (reducers) without needing to use redux (the library) at all. Lifting state up to the right container component so props flows down rendering when necessary.