Think of education until high school as a testing ground. Students take the subjects and can see what it is they like and don't like.
You already know what you want to do in your future and that's great since you get to save a lot of time, but there are many students who have no idea what they want to do. If they are forced to choose a career early on only to find that they don't actually like it, then it will be much harder for them to switch since they wouldn't have learned what is required for another career.
This is why everyone is taught the same thing at the beginning. Students get the foundation education and once they reach 10th or 11th grade, when they supposedly have a better understanding of who they are, they get to choose the career they want to study in college.
Regarding homework, I know it's pain on the behind but it is necessary to apply what you learned in class so that you can master the subject. Already mastered it? Then it should only take minutes to complete.
I always compared homework to a dentist appointment. I know its good for me but I don't wanna do it.