Exactly. And Nakamura takes in that video the position that 100% is the perfect game. It's not. 100% means you made exactly the same moves an engine would made, but engines sometimes have two best moves with only a minimal preference for one of them. Those decisions are the ones that made Nakamura best games "mere" 80'ish%, in less important moves he did the second bests according to the engine.
If you are a top player and cheat, you would only require a couple of decisions here an there in complex positions, and the games would be still at roughly 75%. But if you don't fully understand the line, or you're not in the zone, and the engine suggest something crazy (but winner) you need all the following moves.
If you are a top player and cheat, you would only require a couple of decisions here an there in complex positions, and the games would be still at roughly 75%. But if you don't fully understand the line, or you're not in the zone, and the engine suggest something crazy (but winner) you need all the following moves.