[kcartlidge]

> I also didn't realize it installed things globally

It doesn't. It's a subtle distinction but the 'blame' doesn't lie with pip. When you do a pip install it does it in the context of the python interpreter you're using.

If you use your global python you get an installation in a global context from pip. If you use a non-global python you get a non-global installation from pip. And this is what venv etc give you; a local interpreter, which means the associated pip installs in a local context (a separate one for each venv).