I don't really understand the use case and wonder if containers are the right tool here at all.

Here is my main use case. I have lightweight services that I need to update and deploy regularly (until I movee to K8s or a proper production env). Using pooshit, I can push my entire local dev folder to a remote server then destroy the old image, rebuild the new image and spin up a new container with one call. Your config file contains your remote config. You need nothing in between you and your remote server and it only relies on SSH and docker, nothing else, no middleman, repos, and no deployment containers running on your VM.