"I already know it" = "I insist this is true even if it's actually not which I can't possibly actually know."
Again, you might be correct, but you are in fact just speculating. None of us actually KNOW, in any absolute way, the exact details and problems. All we can know is what is in front of us, which we then speculate about. But it is very clearly just speculation, because there is a great deal we are not privy to.
Yes, perhaps you are correct. Perhaps if you were in charge, those changes would have the desired effect. But suggesting "I already know it" is suggesting some 6th hockey sense, where you, without being privy to all information, happen to hit a vague bullseye with a random throw of the dart. You know the general direction the bullseye and target are at, you know sort of where you need to throw, and you launch hoping to hit the mark.
But in reality, it's still just speculation. And also, rarely are such issues due to a lone causation. We are talking about a multivariate phenomenon here. Meaning, it absolutely isn't and can't be just one thing. We can only list the possible variables, but we can not know with any certainty which variables are actually having a substantial effect.