Two words: Source maps. You don't get that with concatenation. As others point out, Browserify is not complicated at all. Moreover, it gives you an actual pipe

Two words: Source maps. You don't get that with concatenation. As others point out, Browserify is not complicated at all. Moreover, it gives you an actual pipeline process for creating the "bundles" of code. It supports transformations such as brfs and envify, which let you share more code between the client and server. And it's super trivial to set it up so that bundles are served dynamically (via Node) during development, so that you only have to reload the page without running any kind of watch process, but have it generate static, minified versions for production.