It's go; that could be trivially done with a script.
Heck, you can even cross compile go code for any architecture to another one (even for different OSes), and docker would be useless there unless docker has mechanisms to bind qemu-$ARCH with containers and binfmt.
I'd argue that having it in a Docker container is much easier to integrate with the rest of many people's infra. On ECS, K8s, or similar? Docker is such an easy layer to slap on and it'll fit in easily in that situation.
Are you running on bare servers? Sure, a Go binary and a script is fine.
Yep, it's using docker as a means of delivery really. Especially in larger organisations this is just the done thing now.
I understand what the OP is saying but not sure they get this context.
If I were working in that world still I might have that single binary, and a script, but I'm old school and would probably make an RPM package and add a systemd unit file and some log rotate configs too!
Heck, you can even cross compile go code for any architecture to another one (even for different OSes), and docker would be useless there unless docker has mechanisms to bind qemu-$ARCH with containers and binfmt.