I've messed up my python installs very badly

[mwr]

@Rubiksmath

Well, my thing is that many of my projects have environments already. So I am unsure what to do there.

You can switch to using portable python builds

Publish Linux installer on python.org

FWIW I think should core CPython adopt GitHub - indygreg/python-build-standalone: Produce redistributable builds of Python and make it part of the release process would solve this need for 99% of the users

Also, importable modules can be controlled not through venv but through sys.path.
But this is another much more difficult question.