man useradd states:

useradd is a low level utility for adding users. On Debian,

administrators should usually use adduser(8) instead.

Note the low level utility

To add a user, use adduser instead. It's a more high-level utility.

Moreover, looking at the -d option:

   -d, --home HOME_DIR

       The new user will be created using HOME_DIR as the value for the

       user's login directory. The default is to append the LOGIN name to

       BASE_DIR and use that as the login directory name. The directory

       HOME_DIR does not have to exist but will not be created if it is

       missing.

The directory will not be created if it is missing.

Generally, keep away from useradd, use adduser instead.