This isn't about whether or not one can provide a straightforward answer. It's whether or not one is even aware that the question has a non-obvious answer. Saying "actually, that's a complicated question" is a more virtuous answer than providing some unsubstantiated, ad-hoc response that falls apart under the slightest scrutiny.

It most poignantly ties in with imaginary expertise as both arise from the illusion of explanatory depth, (i.e. "I am familiar with this, therefore I understand it")