In the context of your question Hub makes sense, as it is something Docker maintains that most podman users still rely on
> Compose files aren’t a replacement for Docker Hub.
Correct, but most compose files refer to Docker Hub.
You seem to be highlighting that alternatives, which I don't dispute, but most people are overwhelmingly using the services that Docker maintain. That's the answer to your question. Read up a few replies if you've forgotten the context.
Most stuff is not published on Quay; most podman users use Docker Hub or Compose files.