Like when you send a .7z instead of a .zip or .rar to a friend or a teacher because that's what your computer has installed and they're like "Oh No, not one of those, now I have to install 7Zip" even though the same program that opens .rar also opens .7z I feel like people are way more annoyed when they receive a .7z
you can pipe a shell command directly into the archive. they're also a standard archive format understood by most computers on earth.
or maybe this was a joke reply.