Facebook made React like this because of these requirements: they wanted their chat application that requires various real time small updates to multiple parts of the page to run quickly where a wipe and rerender approach is too slow, while being declarative because their constantly rotating staff had trouble writing it imperatively.
To meet this requirement you need:
a constantly revolving staff that are of varying degrees of competence and can't write non-buggy imperative code in the few situations you can't just wipe and re-render
a situation in your application where wipe and re-render is too slow, AND the situation is too complex to hand-write the individual updates manually
The other decision React made that was wrong was the need for JSX. They decided on JSX because they made a mistake many people make when just using the pure JavaScript API for creating components - they tried to make it nested like html using a fluent/chained call approach. As it turns out, trying to keep the nested HTML structure is not necessary for readability.
My library is github.com/thebinarysearchtree/artwork
After using it, it makes React look like SOAP vs JSON. It has less code, runs as fast as you can get, and everything is in your control because it is just web components with some functions to handle the repetitive parts.