We've made serious efforts over many years of building content managed websites to ensure that the sites we build are sustainable for our clients. It's easy for all teams involved in digital development to generate exciting ideas and features.
When we first started using Agile to manage our projects, we were delighted with the idea of valuing "working software over comprehensive documentation". In waterfall project management, documentation was used all too often as a way of simply mitigating risk. So reams of paper were wasted, as documentation bloated and became unmanageable in any practical sense.