Webpack isn't perfect and has some pitfalls.
The documentation is awful. I won't sugarcoat this. The language is often confusing, such as "webpack takes modules with dependencies and generates static assets representing those modules." What? Even the page layout is problematic, with random sidebar entries you can't click on, and animated logos while you're trying to read.
The source code is similarly painful.
Configuring Webpack is a minefield for newcomers. The configuration file syntax is confusing. It helps to look at established examples from boilerplate projects.
Webpack is maintained mostly by one person. The rapid community adoption and the thrust into the spotlight means the ecosystem lags far behind the maturity of React. This has side effects, such as the poor quality of the documentation.
Webpack introduces a nasty mini language in a string: require("!style!css!less!bootstrap/less/bootstrap.less"); This syntax is almost never used, and barely explained, but it's all over the documentation. This string language is one of of Webpack's biggest design flaws in my opinion.
