ReasonReact has been used in production for 3 years now, with billions of page views a day. I'd still call it immature in many^[1] regards :D

The particular point of this project was to prove that each successive simplification that my friend proposed, i.e. avoiding Webpack for native ES6 modules, using lit-html instead of React, etc. introduced its own complexity. I'm not saying that these were all bad ideas, but just that they're fundamentally tradeoffs. I'm quite sure lit-html is a great stack. But it's not "better" than React any more than React is "better" than Angular.

[1]: Lack of async/await, or its equivalent, let+ in OCaml 4.08, is a big one. Mediocre typings for browser APIs is another.