If your argument about education is instrumental, that is, if you think that the primary goal of education is to create economic mobility, then your idea of success is necessarily limited. Education by itself cannot alter the fundamental relationships of property that underlie class in general and social inequity in particular. Education wasn’t ever supposed to do that, though; it was supposed to make these structures more visible.
The liberal, instrumental, view of education, then, which sees education solely in terms of vocation, necessarily has limits, as John Marsh, has recently argued in “Why Education is Not an Economic Panacea.” Marsh, though, seems to be reifying social processes, assuming that an uneducated society is more or less identical to an educated society. If learning doesn’t help in the labor market, apparently, it doesn’t help at all.
Yet, arguably, despite what Marsh calls an educational consensus from right to left, the U.S. has never committed itself to the creation of an educated society. Even the crudest measurement— the numbers of people with college educations– shows that even after more 5 decades of post WW II property and expansion, we remain a society in which 2/3’s of the population has never attended college. The job remains undone.