" UNIX, however, has no basic listing command, and instead uses a program meant to do something else.

Thus if you want to list the contents of
a file called "HappyDays," you use the command
named "cat":
cat HappyDays

Why cat? Why not’? ..."

'The trouble with UNIX: The user interface is horrid' Donald Arthur Norman
https://www.researchgate.net/publication/202165676_The_trouble_with_UNIX_The_user_interface_is_horrid