If this works `git clone me@github.com:me/mine.git release_01 && ln -s release_01 /var/www/me/mine/current` then your Docker builds should also be extremely quick. Where I have seen extremely slow docker builds is with Python services using ML libraries. But those I reallly don't want to be building on the production servers.

"ECS would have worked for 99% of these apps, if they even needed that."

I used to agree with that but is EKS really that much more complicated? Yes you pay for the k8s control plane but you gain tooling that is imho much easier to work with than IaC.