Do university grades matter?

I am right now in a business (economics major) school. I know I need good grades to get a good coop placement but at the end of they day does this crap really matter? Does GPA have any impact on one's ability to get jobs? School right now is just agonizing right as I end up spending like 6 hours a day doing boring work with no student or professor interaction. I start to feel like my time would be better spent on learning more useful skills (like stock market knowledge or msft excel) because at the end of the day, none of this school bs is going to matter post graduation. Anyone out there with a business background land a solid job with bad grades? Or since I am convinced school is bs, should I be trying to become self-employed? I feel directionless but knowing whether or not I should be focusing on grades would be super helpful, thank you!