[rjsw]

An executable of 'cd' wouldn't do anything useful, it could only change its own idea of working directory then exit, the shell or other executable that invoked it would be unchanged.

[stjohnswarts]

why couldn't it call an api in the shell to change directory?

[remram]

What would that improve? And what happens if you call it from another shell?

[stjohnswarts]

I never implied that it was better or worse but that it was possible