Personally I strongly disagree that you need to be "all in" on the React ecosystem if you don't want your knowledge to evaporate (as the author puts it):
I've been using React since 2015 when it was still in beta, so I witnessed the evolution and invention of the whole ecosystem around it firsthand.
And while it's true that the team and community introduced many new tools and technologies, you could probably still use the original React documentation from 2015 to build a simple app (as to my knowledge no backwards-incompatible syntax changes were introduced).
Also, for 99 % of apps you probably don't need the full-blown React stack like React Router, Redux, server-side rendering, hot reloading, transpiling with Babel, bundling with Webpack2 etc. I routinely build small React apps for websites (e.g. for contact forms) using just vanilla React.js (actually Preact.js as it has a smaller footrprint) without any of the amenities listed above, and sometimes I even write old-style ES5 code and use JS-based tags instead of JSX.
So please only introduce additional complexity (in form of tools, libraries and add-ons) if you really really need it. The more complex your toolchain, the more effort you will spend just maintaining and upgrading it instead of doing productive work (frontend devs who tried upgrading Webpack and Babel.js to the latest version in an existing project with many dependencies probably know what I'm taking about).