A venv does *not* create a replica of a python installation directory. Files shared with the main Python installation are not copied nor linked. This goes for the standard library, as well as the libraries and headers.
(*Executables* are an exception; they're copied, since a venv needs them on the PATH.)

Copies would take up unnecessary space, and not all operating systems support symbolic links (and we don't want another platform-specific difference), so the shared files are only referenced using pyvenv.cfg


If you point to the macros you're using, I can take a look at how they could be improved.