This is true, but it is also possible to read a zip file in streaming mode without using the central directory at the end of the file.

Yes, that's a good point, thanks! My understanding is that it's possible for files to have been deleted or replaced in the central directory but still be present in the ZIP file, but I haven't encountered such a ZIP file in the wild myself. I did write the parent node before I had looked into the ZIP file in question to discover that it only contains a single file.