From the first sentence: "we get a lot of questions about how to build large applications with React and how to integrate external APIs" Large application strucutre, external integrations...not "Hello World"
Of course there is no need for multiple environments, or a robust testing setup, or an icon font, or 6 different webpack loaders to learn the basics of React. This is not a tutorial on the basics of React -- this is written from the perspective of a large production level application. And that "overhead" and "insanity" are helpful for real projects that are staffed by more than one person and need to last more than a week.
It seems absurd that it might take you 2 hours to setup the environment before you get to hello world. But if you are planning to use this as the foundation of a 6 month long project, 2 hours to get everything setup in a sane way is not an issue.
There is absolutely churn in the JS world and some of it does seem unbelievable because things haven't contracted and settled into a steady-state. But don't just levy a blanket "lol fuck javascript tooling" every time you see a complicated setup process; you are doing yourself a disservice by not critically evaluating the choices the author of this post made and determining for yourself if they will benefit your project and/or learning efforts.