Eliminating running applications which talk over the network from deployment is a huge gain. Making things happen once rather than per-server is also a huge gain.
On one server, cloning and installing things from the internet is all fine. Installing/upgrading hundreds at a time means you get to see how unreliable package management can be. You also have to guarantee enough bandwidth to the repo/package server to handle everything, or implement orchestration so servers don't install the same thing at the same time. At scale this matters.
On one server, cloning and installing things from the internet is all fine. Installing/upgrading hundreds at a time means you get to see how unreliable package management can be. You also have to guarantee enough bandwidth to the repo/package server to handle everything, or implement orchestration so servers don't install the same thing at the same time. At scale this matters.