Imagine if filesystems didn't have path hierarchies. Every directory would be represented by an integer in a flat hierarchy. Whenever you want a new directory for your application feature, you'd pull request on someone's Github repository to reserve a new integer so that others don't use the same for a different purpose. If you don't know the meaning of a directory number on your system, you can always check that one Github repo. There's also no filenames, so you can't replace an existing file, only add to the same directory. It's wonderful that paths exist.