OCI image repositories are pretty ubiquitous nowadays and are trivial to setup.
I am sure that a lot of people have them deployed and don't even realize it. If you are using Gitea, Gitlab, Github, or any of their major forks/variations of you probably already have a place to put your images.
So I really don't know what the advantage of 'single file distribution model' is here.
This is probably why people don't bother sharing tarballs of docker images with one another even though it is has been a option this entire time.
If you're sharing with lots of people registries are great.
If you're deploying to a server, I don't see a point in setting up a registry, regardless of how trivial it is. It seems even more trivial to just send the deployment package to the server.
You say "the" server as if it were a single long-lived host? I haven't had a deployment target like that in almost 20 years. My world is ephemeral and redundant so putting things into a registry where they can be pulled from as needed tends to be the option.
Lots of places run like you did 20 years ago and have no reason to introduce unnecessary complexity where it is not needed. The world I'm living in mostly uses dedicated servers and most projects I work with have better uptime and performance than the average unicorn running on k8s (or whatever the latest fad is). I imagine GP has similar experience.
I am sure that a lot of people have them deployed and don't even realize it. If you are using Gitea, Gitlab, Github, or any of their major forks/variations of you probably already have a place to put your images.
So I really don't know what the advantage of 'single file distribution model' is here.
This is probably why people don't bother sharing tarballs of docker images with one another even though it is has been a option this entire time.