As a former architect, I am a strong believer in having strong foundations. Without a strong/stable foundation anything you build on top will be weak and might collapse. Information technology is no different. Without a stable environment, anything you add on top will be prone to issues.
Below is an illustration of what I believe the fundamentals are for any environment. As you can see, each step sits on top of another. Thus without the one below, you can move up the pyramid. Each step is dependent on each other.