all files are either text, binary blobs or archives (zip), no exception
I personally knew about this when I needed to extract all images from a Word document in 2015, I had the idea to rename the extension to .zip and wow a conveniently placed media folder !
since then I renamed countless file extensions to zip, just to test. it worked nearly every single time
If you're including binary blobs as one of your options, then both text and archives are just types of binary blobs :)
Hah! That's also how I first learned about the zip trick with pptx. Had never considered it generalizes outside of OOXML files. I'll give it a try next time I'm poking around another file format
Software like 7-Zip supports many formats, even ones that are not usually treated as archives, and recognises them by magic bytes rather than extension. You can for example add a zip extension an EXE file, and 7-Zip will open it.
A much more robust way to figure out what's in a file is using libmagic, accessible through the `file` command on *nix. I don't know if there's an alternative Windows though.