Selfhosted

I feel that a lot of people here are missing the point. Docker is popular for selfhosted services for a few main reasons:

1. It is one package that can be used on any distribution (or even OS with a Linux VM).
2. The package contains all dependencies required to run the software so it is pretty reliable.
3. It provides some basic sandboxing against non-malicious services. Basically the service can't scribble all over your filesystem. It can only write to specific directories that you have given it access to (via volumes) other than by exploiting security vulnerabilities.
4. The volume system also makes it very obvious what data is important and needs to be backed up or similar, you have a short list.

Docker also has lots of downsides. I would generally say that if your distribution packages software I would prefer the distribution's package over the docker image. A good distribution package will also solve all of these problems. The main issue you will see with distribution packages is a longer delay before new versions are made available.

What Docker completely dominates was previous cross-distribution packaging options which typically took one of the previous strategies.

1. Self-contained compiled tarball. Run the program inside as your user. It probably puts its data in the extracted directory, maybe. How do you upgrade? Extract and copy a data directory? Self-update? Code is mutable and mixed with data, gross.
2. Install script. Probably runs as root. Makes who-knows what changes to your system. Where is the data, is the service running? Will it auto-start on boot. Hope that install script supports your distro.
3. Source tarball. Figure out the dependencies. Hope they don't conflict with the versions your distro has. Set up users and setup scripts yourself. Hope the build doesn't take too long.