uv solves many problems, but one textbook case is the problem of running some arbitrary Python-based command-line tool, where 1/you don’t have any Python interpreter installed, 2/your OS-provided Python interpreter isn’t compatible with the tool, or 3/you want to run single or multiple tools from any arbitrary folder where your data already is, as opposed to adapting your workflow to fit the virtualenv or running the risk that two tools have conflicting dependencies that would make the virtualenv not work well.