In early grades I considered most homework a waste of time. Even in my high school years (and I went to a good private high school), a good portion of what was assigned did nothing to help a student actually learn the material that was taught in class.
I have an advanced degree, a professional license, and I think I've been pretty successful in my career. I'll tell you here that what I learned outside of school was far more important than what I learned in the classroom and in my homework assignments.
The most useful things I learned were done as punishments rather than lessons. Typically writing the multiplication tables from 1 to 12 ten times each. Really drills into you that 7 x 8 = 56. etc.
Now the kids pull out calculators to do such things while I just look at the problem and have the answer. Learning by rote in the early years gives them a good basis to build on in the later years.