My example was mainly on a straight road because it's easy to understand. It applies to curvy roads where you won't see ahead too though. As someone driving, you should never drive faster than what you can see ahead and be able to stop in time. I kind of imagine what I'd like to call a "meteor" incident. Would I be able to stop in time if a meteor randomly crashed just outside of my vision ahead in a turn? If not - probably going too fast. (It's not uncommon to meet a "meteor" in the form of a car) One could call that "speeding" but that's not what it is colloquially. (Speeding to most is going 1+mph over the posted limit)
If the visibility is good, there's nothing wrong with going faster. Aggressive speed limits make more sense to be followed when there's very limited visibility, high chance of stops, people crossing the road, intersections, etc.
But if visibility is good, I don't see it making a difference much in what speed you're going.