Docker is not a good solution. Many security focused systems (important for self-hosting) are on FreeBSD. FreeBSD doesn't allow docker, because of it's major security vulnerabilities.

Docker is great for getting toy projects to work somewhere as a last resort, if the dependencies are strange and you need a convoluted (read: badly thrown together) environment to set up the app.

A well made application should not need docker to run.

What do you mean? The world is running on containers.

Docker and I are not friends. The quickest way I found to fill up my limited VPS hard drive was to install Docker. All the work arounds to limit it failed. Then there's the whole lack of concrete control over iptables, where a tiny mistake can open you up to all sorts of horrors. So, it's great that Docker works for many, but I get the exact opposite of warm and fuzzy for it however.

Perhaps Nix could help? It's great for configuration and reproducible builds without the overhead of containers (which in practice aren't often reproducible).