(disclaimer: I'm leading the Docker Model Runner team at Docker)

We are not packaging models as Docker images, since indeed that is the wrong fit and comes with all kinds of technical problems. It also feels wrong to pure package data (which models are) into an image, which generally expects to be a runnable artifact.

That's why we decided to use OCI Artifacts, and specify our own OCI Artifact subset that is better suited for the use case. The spec and implementation is OSS, you can check it out here: https://github.com/docker/model-spec