Reproducible? No. Most Dockerfiles are incredibly unreproducible.
Yes, baking doesn't work the same at sea level vs say denver colorado @ 1 mile, but pretty much you can share your recipe with friends and save them lots of time.
It is possible to get to reproducibility though, by involving lots of checksums. For example you can use the checksum of a base image in your initial FROM line. You can download libraries as source code and install them. You can use package managers with lock files to get to reproducible environments of the language you are using. You can check checksums of other downloaded files. It takes work, but sometimes it is worth it.
Docker was good enough, simple enough, and got the job done. It won for good reason, but the next generation should learn from it's mistakes.
At least they mentioned it in their apple:oranges comparison.
there's also the global namespace thing. "FROM ubuntu:18.04" is pretty powerful.
I run a proxmox server with LXC but if I could use a dockerfile or equivalent, my containers would be much much more organized. I wouldn't like to pull images from the internet however.