I wonder what sort of container registry are you looking for. There are a few alternatives to Docker Hub nowadays. For instance, GCP’s is quite affordable and straightforward.
I don't mean for hosting custom images—I mean for using it as a cross-distro (indeed, cross-OS) very up-to-date, server-oriented package manager. That's most of what I get out of it, right now. It's currently, maybe, my favorite Linux package manager + package repository, even if that's not its core purpose.
It's the container registry that I'd miss, not the actual container functionality, and that's what would have me reaching for Vagrant and distro packages again until something similarly good arose (or maybe there already is a viable replacement, which I'd find via search in short order if I actually needed it)