I assume everyone knows what Observation Haki is, regardless, I’ll explain what it is briefly. It’s the power to sense people and also divine or perceive their next premeditated action of any kind before hand. Premeditation implies having consciously decided upon an action, and then physically committing to it; any action that isn’t of this nature (in other words, that isn’t a premeditated action) cannot be foreseen by Observation Haki.
Luffy decides to punch Satori, Satori perceives he’ll stretch before he even does so.
The Misconception follows the premise that Observation Hak can be used anytime under “any circumstance”. There’s a bit of nuance to this, and that is, it can’t be used any circumstance, but only under specific conditions.
Before I go further, I think it’s established that a character that lacks Observation Haki, but possesses speed that far exceeds that of an Observation Haki user would in effect render foreseeing the future redundant.
He was too fast for her to physically keep up with despite being able to foresee Luffy’s premeditated actions; she was unable to react quickly enough despite foreknowledge.
This then begs the question as it’s the most common scenario. What happens when the opponent is:
Does Observation Haki still offer an advantage in battle? This misconception leads one to embrace the idea that because the Observation Haki user can see the activities of the non-Haki user before hand, therefore, they possess an advantage. In theory, yes, in practice? We shall see.
The problem is the theory is not applicable in practice; we’re met with contrary results/evidence in the Manga every time we see Observation haki users clash against those who do not possess it in the heat of battle.
In the heat of battle, can any advantage be obviously or remotely distinguished? Can we even tell any difference between both fighters in the event we weren’t informed one is or isn’t an Observation Haki user? If the result isn’t clear, this animation re-enacting this scene makes it clearer.
Point being made is we see no evidence of Observation Haki being useful or effective in the heat of battle. Gan Fall despite lacking Observation Haki showed he was on par. Is it that Gan Fall is a superior fighter? Not at all, more to do with a case of the limitations of Observation Haki, otherwise, Shura would have held a clear advantage. The irony is Gan Fall was somewhat superior, albeit, marginally.
Even Katakur’s Observation Haki functions the exact same way. As much as he can see far into the future, even he cannot break the mechanics that govern Observation Haki:
The future can’t just be seen in general. If a bomb were to explode, he’d have to see it in conjunction with someone, otherwise, he can’t predict it.
He can only see it when he’s not multitasking which is why concentration is vital to Observation Haki. Any form of perturbation breaks concentration and ability to foresee what the opponent is doing.
He can only see a bit into the future, not far ahead. Further than the average user at the very least. This is why when Pudding is crying, he has to ask why she’s crying because he can only see the future in conjunction with people.
Observation Haki can only be used when solely Observing and when entirely focused on Observation Haki. It can’t be used whilst exchanging attacks because committing to an attack requires focus on attacking impeding ability to focus on Observation Haki.
This is the principle behind Observation Haki, otherwise, it becomes impossible to understand why:
All the situations in which Observation Haki has blown us away have been in situations where the user was simply observing and not committing to an attack At the very best, if they have enough time to Observe the opponent’s movements like Satori did to Luffy, they can counter or simply evade, but in exchanges? It based on evidence, is impossible.
It is also worth noting Observation Haki is used to observe others and can’t be used to predict one’s own actions, therefore how can one predict their own attack fails? This is also part reason Observation Haki doesn’t function as many assume.
*Theory by Hannibal Psyche