Dockerfile provides as much reproducible environment as bash shell script.

This is why I have beef with docker, it was marketed to solve multiple things, but ultimately it becomes over-glorified zip file. It absolutely fails in reproducibility and I constantly see scenarios where Dockerfile that worked one day broke another day, or it worked on one machine and broke on another and so on.

Yes, you can put extra effort and make your dockerfile reproducible, but similarly you can make a reproducible bash script.