React was built by Facebook. Facebook has 1 billion users. If you're looking to build a fast, simple, web app look at rails or Phoenix, not React.
Webpack isn't React, Redux isn't React, ES2015 isn't React. They're commonly used with React and add complexity to both your architecture and build step, but you're not required to use them.
This tutorial is getting a lot of negative replies because it's a tutorial on all those other things in addition to React. It takes 90 pages before you write React code because the author spent a lot of it explaining how Webpack configurations work.
Of course I also like to stay employed and react is the most in demand framework right now.
Ok, granted at some point you might want to pass your build through Browserify and Babel. No worries, both of those things are one liners in bash.
On the other hand, if you spend most of your time trying to make your build process the holy grail of hot-reloading webpack ES2020 isomorphic madness then you're not going to get much real work done. No one told you to do that though, and you can't blame React either. But even that isn't complexity. It's just annoying setup stuff. Real complexity grows with the scope of your app.
Of course, if all you're building is a static web page then I can see just using some HTML and CSS. But if you want to work professionally as a web developer then you need to know javascript and at least one major framework. You can not stay employed as a "full stack dev" if all you do is write an a couple HTML and CSS files and serve them with python httpSimpleServer.