What does it mean that flat is better than deep when possible?

Simpler hierarchies with fewer levels are easier to navigate and maintain.

Example: A team lead inherits a project wiki organized seven levels deep: Company > Division > Department > Team > Project > Sprint > Task. Finding anything requires navigating through five intermediate folders, each demanding a decision about which subfolder to enter. She restructures it into three levels: Team > Project > Pages. Every page is now reachable within two clicks. Documentation usage triples in the first month — not because the content changed, but because the hierarchy stopped punishing people for trying to find things. The information was always there. The depth was hiding it.

Try this: Take a hierarchy you use daily — your file system, your task manager, your note-taking structure, your email folders, your team org chart. Count the maximum depth: how many levels exist between the root and the deepest leaf? Now ask two questions for each intermediate level: (1) Does this level help me find things faster, or does it add a decision point that slows me down? (2) If I removed this level and promoted its children one level up, would I lose meaningful organization or just lose nesting? For every level where the answer to both questions favors removal, flatten it. After restructuring, use the hierarchy normally for one week and note whether navigation feels faster, slower, or the same. Record the results.