From Python's official documentation for -m option
As with the -c option, the current directory will be added to the start of sys.path
But won't this behaviour need to be changed for every command pip invokes? If we could somehow skip the package if it is present in the cwd at the start of getting packages. Then, the packages provided to each of these commands would be just those which are not present in cwd.
I am not too familiar with pip's source code, I am diving into it to know more. Any kind of pointer will help.