Where I grew up, it was policy to unconditionally promote everyone through the 4th grade, and after that to start holding back failing kids.
For late elementary and junior high, I don't remember whether or not homework was a large enough part of the grade to fail you if you took a 0 on all of it. In high school, I think homework was a small portion... something like 10-20% of the grade. So you could blow off homework if you aced everything else. You had to get at least a 70 average to pass (we didn't do D grades), so if homework was 20% then you had to get at least an 88 average on everything else in order to pass the class. And I think I have vague memories of homework being 30% in some of my high school classes, which means you'd have to perfectly ace everything if you wanted to take a 0 on all your homework.
And there could be consequences for extracurriculars if you were taking low grades in your classes. I remember that in junior high, you could only go to the school dances if you had at least in 80 in all your classes, and in high school, if you were failing even one class you couldn't participate in any school sports.
For late elementary and junior high, I don't remember whether or not homework was a large enough part of the grade to fail you if you took a 0 on all of it. In high school, I think homework was a small portion... something like 10-20% of the grade. So you could blow off homework if you aced everything else. You had to get at least a 70 average to pass (we didn't do D grades), so if homework was 20% then you had to get at least an 88 average on everything else in order to pass the class. And I think I have vague memories of homework being 30% in some of my high school classes, which means you'd have to perfectly ace everything if you wanted to take a 0 on all your homework.
And there could be consequences for extracurriculars if you were taking low grades in your classes. I remember that in junior high, you could only go to the school dances if you had at least in 80 in all your classes, and in high school, if you were failing even one class you couldn't participate in any school sports.