I engaged in math competitions and such as a kid, I hope we can put this into the realm of "higher achievement".

I dont think minimum standards or curriculum moving accross grades have all that much to do with what competitive higher top does. The higher top require way more knowledge then what standards require. And more importantly, it requires more depth and speed.

High achievers are expected to know so much more then standards and to apply it in much higher variety of situations to compete.