Your Olympian gold archer bro is competing on a fantastic level where people run at supersonic speeds and have physical strength to slap down mountains. In general, having an actual understanding of your martial skill helps, and in some cases, helps a lot, but Joe with his massive DEX will still perform much better. 

So basically, when stats are equal, personal skill matters. When stats are grossly unequal, personal skill doesn't matter, assuming all else is equal. DEX plays in for manual people as an 'innate' understanding of how things will play out if one takes x action. Think of it as 'guidelines'? When it comes to crafting though, DEX works to influence percentile success rates. For combat, especially melee combat, the line is blurry.