It's not just about installing a few packages with the package manager. You have system specific configuration, ranging from services to users to file systems

It's not just about installing a few packages with the package manager. You have system specific configuration, ranging from services to users to file systems and more, sometimes at odds with the state of a security patched/updated machine at any point in time. The way you configured the state of a machine 12 months ago might not be reflected when you build, update, and configure a machine today. This disconnect between installs gets compounded when you have to randomly log in and make minor tweaks to keep up with your ever-changing application specs (tweaks which rarely get documented), causing you or your successor to scratch their head wondering what steps are missing compared to before when doing a new build. This gets even more complicated when you build large clusters meant to scale, and can't afford to spend the time it takes to individually configure each machine. Orchestration aims at fixing this by giving you a way to bring the state of a freshly installed machine to the correct state of your production environment in an (ideally) consistent and repeatable manner, which is the whole point of all these fancy new products we're seeing these days.