For the sake of some discussion, I think these boilerplates are a footgun for most developers. If you're a new React developer, your goal should be to learn how each dependency in a project fits together, and you should be starting your first few projects with literally zero depencies and growing them organically as you need (not want) new tooling.
If you're an experienced dev, you've already got your own boilerplate set up just how you like it.
So the only two use cases I can see for these boilerplates are: Rookie developers should use them as examples for how to implement a specific dependency in an existing project, and experienced developers should only really use them as a source of quick ideas for tooling they may have missed that would be useful to their existing projects.
Actually basing a project off somebody else's boilerplate is a huge mistake, in my experience.