Besides what you already noticed (that most software can be found packaged for Docker) here are some others:

• It’s much lighter on resources and efficient than virtual machines.
• It provides a way to automate installs (docker compose) that’s (much) easier to get started with than things like Ansible.
• It provides a clear separation between configuration, runtime, and persistent data and forces you to get organized.
• You can group related services.
• You can control interdependencies, privileges, shared access to resources etc.
• You can define simple or complex virtual networking topologies between containers as you like.
• It adds extra security (for whatever that’s worth to you).

A brief description of my own setup, for ideas, feel free to ask questions:

• Router running OpenWRT + server in a regular PC.
• Server is 32 MB of RAM (bit overkill for now, black Friday upgrade, ran with 4 GB for years), Intel CPU with embedded GPU, OS on M.2 SSD, 8 HDD bays in Linux software RAID (MD).
• OS is Debian stable barebones, only Docker, SSH and NFS are installed on the host directly.
• Docker is installed from their apt repository not from Debian’s.
• Everything else runs from docker containers, including things like CUPS or Samba.
• I define all containers with compose, and map all persistent data to host storage. This way if I lose a container or even the whole OS I just re-provision from compose definitions and pick up right where I left off. In fact destroying and recreating containers cleanly is common practice with docker.

Learning docker and compose is not very hard esp. if you were on the job.