What if Plato thought that (at least part of) the truth was that it was more beneficial for people to think and seek than to be told the pre-canned truth?
And what if was wrong about that? Or is it your assumption that Plato was right about everything, and so therefore he must be right about that particular idea?
As to Aristotle's specific empirical claims in the realm of biology, the great majority have been confirmed by modern science.
Here's a further point. The question with Plato's dialogues is not whether a personal dialogue with a philosopher might be the way to go, but rather is a published dialogue better than a published work of straightforward exposition.
The fact that people disagree so much as to Plato's ideas, but far less over works of straightforward exposition, would seem to indicate that, when it comes to written texts, the latter is far superior.
In fact, the dialogue boosters actually seem to believe this. I say this because when they are writing their interpretation of a dialogue, and they get to a point people disagree on, they don't write more dialogue, but rather use a series of propositions to present what they think Plato actually meant.
Beyond that, my impression with the dialogue boosters is that at least most of them are more devoted to the idea of promoting the superiority of dialogue than to rationally determining if Plato's ideas are actually correct.
And what if was wrong about that? Or is it your assumption that Plato was right about everything, and so therefore he must be right about that particular idea?
As to Aristotle's specific empirical claims in the realm of biology, the great majority have been confirmed by modern science.