First off, I must say that Education is very good and i don't dispute the fact that it's very vital and necessary for human development, it can put you in a position to be successful no doubt but being a graduate is not a 100% guarantee for one to be very wealthy, one can be very sound academically but lack some basic skills of acquiring wealth. Also one can still have some good knowledge of certain skills but if there's no zeal or self confidence in earning a living through it then your education on those skills can be said to be a waste since you ain't making effort to earn from it.
Also I've heard several people complain about having good grades, being 1st class graduates but find it difficult to secure good paying jobs, imagine someone struggling to achieve good grades in the university but find it difficult to earn a living and at the end settle for minor jobs while there are many dropouts with good skillsets as well as being creative and think outside the box, and are bosses of big organisations and companies.
Well it's not basically about being educated or graduating with the best grades that makes you wealthy, it's about determination, being consistent and also persistent cause success and wealth are not achieved in one day or immediately after graduating. In as much as you have good grades, you must still improve your skills, not only job skills, marketing or management skills but your critical thinking and problem solving skills.
There are many ways to think about this, imagine being a tradesman for example - you can do many things with a hammer and a screwdriver, but to be truly successful you need the full load of kit which is specialized for every job. Just having a degree is not enough these days, as younger generations are often funneled through this treadmill to make universities richer but pick up less than useful skills. If thousands of people are learning how to be librarians or archaeologists every year, when there may only be less than a hundred jobs available in the field - it makes it hyper competitive to use that specific degree when you get out of university. Many will be resigned to pursuing something that may be less than their ideal job choice.