I too was perplexed, but the main use case seems to be when you want to share a particular configuration or need to be sure that you always use the same set of flags:

> Flags are ephemeral – you have to share the command line or wrap it in a script. Scripts depend on environment, which can break portability. Filenames solve both: the program describes itself, requires zero setup, and any configuration can be shared by simply renaming the file.

[Emphasis added] Although I find a script that wraps the command and calls it more versatile, there might be some value in this idea for some very simple cases, like example #4.