I think you're being downvoted due to strawman ([s]he praised documenting concepts, not the documentation as a whole) but you're right though. I've never dived into my toolchain code (due to missing or frugal documentation) more than I've been forced to with Webpack.
It suffers from tutorial-like instructions and a lack of formal list-like documentation, which leads to conflicting or confusing configurations (very easy since there are multiple ways to do the same thing, shortcuts found in the CLI but not in the configuration, etc.)
I love Webpack, but the documentation is really rough in some places.
> ([s]he praised documenting concepts, not the documentation as a whole)
Exactly. I wish I could help with docs for Webpack, but personally I'm willing to trade extensive documentation for a friendly community. These aren't mutually exclusive of course, but I've seen my share of OSS projects with a bad attitude towards beginners and people who are just missing some detail for the whole thing to click.
Likewise, my point re: boilerplates would be moot if most boilerplates had good docs (even if just a detailed README).