Getting that spec is damned hard.
What do i mean by spec? Basically are you going to build the right thing. A hard problem - if you think it’s easy, it more than likely means you didn’t understand the problem.
The reason pinning down a spec is so hard is because at the macro level, there are very few actual solutions - mostly only trade-offs are available to work with.
In my forty year career I never saw a spec that was anywhere near accurate or complete.
Once it’s been captured what needs to be done (spec) enabling the rest of the team (execute) is comparatively easy.
Fail to spec, and the team can’t execute. They don’t know what needs to be built.
I'm sorry, but it's hard to take your comment seriously when your definition of "spec" is AoC puzzle.