What is "adequate"? Any long term task still hangs the business logic thread - the only thread - unless you fallback to native. At what point does constant fallback to native for implementing what is not possible in JS a detriment to development? You may say, multithreading is an edge-case, but is it? I have not been involved in a single project where actual multithreading was not needed. Also, the way RN is implemented internally, such as async bridge and layout (CSSLayout / "yoga"), it is quite impossible to use native optimized views, such UITableView with reusable views, because this API is designed for synchronous API calls.