This is absolutely a great point, and honestly, I used this exact argument early on in the development of React Native to convince folks that cared a ton about craft and were super worried about performance, that it's more important to make sure you have a reliable application that adds value to peoples' lives, before you even earn the right to start thinking about craft.

My phrasing was somewhat hyperbolic, but I basically said: "Do you honestly think that a person, in the middle of a natural disaster, trying to determine whether or not their family and friends are okay, gives a sh about 60fps animations?"

The real value of React Native is that it allows engineers who know React (and React is really, really easy to learn btw), to build great feeling applications without putting in a ton of effort. Sure, it's possible to get close enough on web, but it's really, really hard to do so.

One of the things we tout in product infrastructure at Facebook is that when building frameworks, you need to enable engineers to fall into the "pit of success". The asynchronous nature of this implementation allows application logic to be run off the main thread by default, which we think is a huge advantage over a traditional web model.