Yes, that too, but GP isn't talking about virtual environments.

Or just run it in a container!

Poetry wins over a container because you have better version control (minimum/maximum specs as per your pyproject.toml file) and makes sure your users get the same build (as per poetry.lock).

Additionally if what you are building is a library, then a container won't fly as you (to my knowledge) cannot publish these to pypi (to make them installable via pip install foo)