What is the problem with an ontological view?

Kant attacks the argument by saying that the analytic is empty and cannot invent new things.
Intuitively, it’s the initial lack of training in such a view, how the hell did you define something and you decide that it exists.
But I don’t understand, causality is my assumption about the world, and I take it for granted that this is how the world behaves, even though I’ve never seen it, as the Grat Yom extended.
Now, let’s assume that causality was not so simple for me, but that I had to prove with a logical proof that this is how I perceive reality, would this be an ontological proof? So, how is the perception of causality that can make a premise about the world different from an ontological view? The only ‘problem’ with the view is that it is not directly accessible to me and I have to do a conceptual analysis to understand that this is how I perceive.
L. A. Kant claimed that conceptual analysis cannot add data about the world, and the answer is that in reality the analysis does not add any data. It essentially shows me that this is how I perceive the world. Anyone who wants to claim that I perceive it this way but in reality it is different should first question causality.
What’s wrong with that?