I think we should question the idea that there is such a thing as "college level work." Are we talkin' physics at MIT and analytic philosophy at Reed College? Or are we talkin' Math 1A and English 1A at Southeastern Nowhere State U?
That is true. But then, isn't it also true that the average person, if he or she goes to college, will go to SeNSU or its community college brethren? So...when we're talking about "college level" work, doesn't it make sense that it means the work an average college student would be doing at an average college (just as "first grade work" means typical first grade work at a typical school, rather than the work HG kids do at gifted schools). And the average student won't be ready for that sort of work until he or she is approximately eighteen, if ever. However easy and trivial the work may seem to us, that does not make it meaningless when a ten year old can accomplish what the average sixteen year old cannot.