You’re conflating “knows the system” with benevolent dictator. It’s not the same. It’s down to whether in a planning or brainstorming session, there is anyone who can say that a plan won’t work or if there’s a better one.

Also it doesn’t have to be singular. You need at least one, in case that person leaves or becomes problematic. That dictator doesn’t always remain benevolent and they can hold a project hostage if they don’t like something that everyone else wants.