Which is better to have? probably academic success. Whilst I know plenty of people who are by not "especially" intelligent who achieved well academically - none of them are by any means stupid... that sort of success sort if guarantees average or above average intelligence.
On the other hand... as someone who is (trumpet blowing...) of above average intelligence who completely messed up University (twice, despite high academic achievement up until that point) through apathy... I can promise you that being intelligent but stuck in a dead-end job is completely soul destroying. I would genuinely rather be a thick as muck some days, because at least then I might be content with the world.
Maybe. I'm not quite ready to write myself off yet, I suppose. Ask me again in 10 years.
For now I'll say... intelligence is not only worthless if you waste it, it's utterly miserable. You'd be better off as an unintelligent, happy worker bee than an intelligent underachiever.
[edited to add] obviously I'm answering this in terms of general high intelligence, rather than specifically "IQ", as I don't think it's a particularly useful tool. I've encountered plenty of people with sky-high mathematical / logical / Visio-spacial IQs (and resulting high IQ scores) who are almost completely void of any form of social or personal awareness. I doubt those people are particularly prone to existentialist issues. Then again, I suspect they're also far less likely to underachieve academically...