Proxmox or even just lazy old KVM GUI for anything that needs to be deployed manually in a VM (Home Assistant, WIndows VM, etc.). Otherwise you can even just spin up whatever manual service you want to run on an LXC container or bare metal host with the correct security settings with systemd and selinux if you want to be extra careful.
Docker/Podman (the superior one lol) is just an automated deployment system in container form (like Ansible). It great for automated deployment without having to manually configure the installation process and worry about upgrades, changes, etc. You can even easily create your own images on the fly just for the purpose of having it run a single service inside a container.
Proxmox equivalent would be like using Terraform/OpenTofu to deploy VMs to do the same thing. Its possible, but just not that common because of the reduced overhead with containers, and well supported deployment images with docker/podman specifically.
Generally speaking, I’ve seen proxmox used more in lab environments were you want to emulate something like a complete network of machines whereas docker/podman has become the defacto server deployment platform.
You’re just much more likely to find software with a published docker container and default docker compose script than the same thing in Terraform or even K8s/K3s.
There’s more *arr tools that aren’t aggregator automation tools than there are aggregator automation tools.
Also It was only funny when using an existing words like "sonar, “radar”, “lidar”. Jellyseerr is dumb, even Jackett was pushing it.
I guess it makes it somewhat easier to associate them as part of a group of software, but now we have stuff like Homarr that is entirely unrelated, but still a useful tool.