Those are good points. Seeing experts that are also experts in explaining things could just lead to a confirmation bias. I am however not convinced that having

Those are good points. Seeing experts that are also experts in explaining things could just lead to a confirmation bias. I am however not convinced that having deep and broad knowledge is a field (aka being an expert) is independent of the ability to explain it in simple terms. Knowledge is a network. Facts that relate to each other. The connection can be horizontal or vertical. Connecting low level understanding with high level understanding to me always seemed to be at the very core of being an expert and with that simple explanations evolve naturally. I think it's hard to discuss the topic because it's hard to define what it means to be an expert. It should be a useful definition and what you are pointing at (producing results) might be more useful or it might not be strict enough (for me), or both.