Just two reasons (there are more): 1) uv is vastly faster than pip. Just using uv pip install -r requirements.txt and nothing else is a win. 2) uv can handle things like downloading the correct python person, creating a venv (or activating an existing venv if one exists) and essentially all the other cognitive load in a way that's completely transparent to the user. It means you can give someone a Python project and a single command to run it, and you can have confidence it will work on regardless of the platform or a dozen other little variables that trip people up.