I'm of the opinion that this far less important than many people think it is -- it's another form of bike shedding. I'd like to get to the point where we have a recommended directory structure that people can agree on, which allows you to jump between projects easily and know where things are, but given the diversity of tools used in the React and React Native communities at the moment that may be difficult to achieve. Ruby on Rails does a fantastic job of this; I think that's half due to the relative stability of the MVC pattern and the Rails implementation of it, and the other half because the structure is enforced programatically and a principle of the framework (convention over configuration).
My advice would be to not stress about it, start with something simple and evolve it over time.