Indeed, to expand on my remark: I wrote Python in academia for ~6 years and then professionally for nearly a decade in data science, data engineering and backend web apps. Virtualenv was fine. Pipenv had a nicer CLI and easier to use dependency pinning. But fundamentally all this stuff worked fine.

Because making external modules cooperate with the system environment is awkward at best (and explicitly safeguarded against since 3.11, since it can cause serious problems otherwise even with "user" installs), and installing the distro's packages in a separate environment is not supported as far as I can tell. And because the system environment is often deliberately crippled; it may not even include the entire standard library.