Wesupportgifted - yes, I agree with what you've said BUT I caution putting a lot of stock into IQ as the motivator or engine. One might have a super high IQ but limited curiosity or much of a drive to create.
Then, there's the issue of 2e kids and that muddies the situation. If you're child is not in the 99.9% but ends up being Jamie Oliver (who's dyslexic, started working at 8 yrs old in his parents' restaurant, and probably wasn't identified as 'gifted' in school).
Traditional, mainstream classrooms are a one-size-fit-all, but we don't all fit that mold regardless of IQ or giftedness.
PG or exceptional kids or those who appear to be pg/eg usually have different needs from the mainstream or norm. A Jamie Oliver (who probably doesn't have a super IQ) is an outlier. He's unlikely to have his needs met by a traditional, mainstream classroom or possibly even a 'gifted' school. The reality is that a Jamie Oliver may need something very individualized and tailored for him to really thrive.