I'm referring not just to what is said but also what is implied. Ben tells us more than just a role in the Old Republic. He tells us that they were the guardians of peace and justice in the Old Republic for over a thousand generations. He talks about how the Empire, through Darth Vader, brought down this ancient order to the point that it has been virtually eradicated. This little scene tells us a hell of a lot about who the Jedi were and what happened to them.

So, in the PT we never got to see Jedi actually acting as diplomats, which, to be honest, seems a bit weird for Jedi Knights to be doing anyway. In my opinion, there was never anything in the PT that would support the conclusion that their becoming generals in the Clone Wars was any kind of perversion. It just happens without anyone or anything suggesting that it may not be such a good idea. The "Jedi Council" turned out to be a bunch of random Jedi sitting about not doing or saying very much of any interest. The link between the Jedi and the Republic is not made clear. It is implied but it still seems a bit ad hoc. The glimpses of "Jedi politics" from Ben and Mannequin are pretty unedifying, demonstrating Mannequin's ignorance and Ben's apparent inability to teach him anything.

My point is that, in a few simple lines, delivered with depth and insight by a great actor, we learn a great deal about the Jedi Order. In three whole films, I don't think the PT managed to convey nearly so much as that one scene in ANH about the antiquity and importance of the Jedi Order in the Old Republic.