Knowledge Bases: Essential or Overrated? I will not promote

Many businesses have a knowledge base for their users or teams. What is the real reason you made one? Was it because customers kept asking the same questions? Or maybe for internal documentation? I am building knowledge base software, and I want to understand what features actually help the most. Some people like simple FAQ pages, others need something more like a wiki. Maybe automation? Search? If you already have a knowledge base, what features do you use the most? If you don’t have one, why not?