I understand both your point of views and I guess I see the confusion.

With Docker, usually you try to pick the base image that is the most closer to your usecase.

For instance, if you intend to run a Python 3.10 script in your final image, you'll start from a python:3.10 base image, since it contains your most important requirement.

But in the article, the author is starting from an "uv" image, and then in the creation process (described in their Dockerfile), they'll install their required version of python.

Which, for many people writing Dockerfiles daily (me included), feels weird: if you intend to run python, why not starting from an image including your python version?

Then, if we look at what uv actually is, it can of make sense: it's an app written in Rust (so not a python app) that can be seen as a _docker for python apps_.

And since the author's focus seemed to be about uv, we can see why they started from an uv image.