Breakers protect wires.. doesn't 83% derating violate it?
It gets kind of weird, but in general residential loads just don't have high enough duty cycle for it to be a concern.  Add up every load in your house, and I doubt you'll be able to draw the full 200 amps (48kw assuming 240V service) for any length of time, even with a house full of guests.  Indeed, I have 200amp service (48kw), but the transformer that feeds my house and about 5 others is only rated to 25kw. The power company asked what loads I was going to power with an upgraded service, and deemed it unlikely that I and all my neighbors would be using more that 25kw for more than a few seconds at a time.  

Ampacity charts also have a significant safety margin.  Drawing more than 175A over a 2/0 wire will get things hotter than desired, but won't cause the cable or its insulating jacket to break down.  

Commercial/Industrial loads are different.  The Code assume that the duty cycle of devices is much higher, and therefore commercial/industrial rated breakers actually trip at 80% of their load rating for continuous draws.  (They allow spikes above that for shorter lengths of time.)