Okay, so to give it to you straight-up, right off the bat, there is no such thing as a full-stack web developer, or at least one which is competently skilled at the specialist level in all the platforms that come together to make up the full-stack that drives web applications driven by dynamic data. Conceptually, yes there are indeed many web developers who justifiably refer to themselves as full-stack developers, on account of having learned how to write code in something like the LAMP stack or equivalent, but in practice there is just too much to learn in each area for anyone to be able to claim knowledge of each of those areas at expert or specialist level.
Sure, you can take me up on this – in fact, let’s dig a little deeper in order to lay the facts bare, shall we?
Now, the bottom line is React software development is so advanced and the library is so sophisticated that you need somewhat of expert knowledge in that field alone if you’re to incorporate its constructs into a decent, modern day web application. Pretty much the same applies to the other languages in the “full-stack,” – they require expert-level understanding for a decent outcome and they’re also changing and evolving quite rapidly, so in addition to all the work you’d need to put in to master each of them, you’d have to stay on top of all the changes, updates, redundancies, improvements, etc.
So at best a full-stack web developer is an expert programmer who assumes more of a project management role, although they definitely have the basic, core technical skills that are required of a good web developer.