I have the same feeling, so I just looked it up and actually uv does support exactly that mode. It works the same as venv and pip but you just prefix a bunch of commands with "uv". Create a new virtual environment fooenv:

   uv venv fooenv

Activate virtual environment on Windows (yes I'm sorry that's what I'm currently typing on!):

   .\fooenv\Scripts\activate

Run some environment commands:

   uv pip install numpy
   uv pip freeze
   uv pip uninstall numpy

If you run python now, it will be in this virtual environment. You can deactivate it with:

   deactivate

Admittedly, there doesn't seem to be much benefit compared to traditional venv/pip for this use case.

This is covered in the section of the docs titled "The pip interface": https://docs.astral.sh/uv/pip/