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
.rar is an awful proprietary format that needs to die, and die soon. You should NEVER use .rar files when sending files to others due to its closed proprietary nature.
.zip is preferable because everyone can handle it by default. 7z is OK because nearly everyone can handle it by default and it is an open format.
Removed by mod