I wish the original post would have started off with why the project exists. They say "have everything in one file", but is there a problem having your JS, CSS

I wish the original post would have started off with why the project exists. They say "have everything in one file", but is there a problem having your JS, CSS, HTML in separate files? CSS, and to a lesser extent JS isn't limited to a single component. Styles are reused across multiple components for consistency, so this "reason to exist" breaks right away. There are enough comments about how people like, or dislike the syntax, etc, but it might help to understand the problem the creator was trying to solve, before just saying "this won't fit my workflow".