Cannot agree with you more!

There is a HUGE difference between the kids who regularly do their homework and those who do not. If you think that there are no benefits to it then you obviously have spent no time in a classroom. The kids who do do it are more likely to be engaged in their work in the classroom and perform better academically than those who do not. Homework reinforces and supports what is learnt at school and it's value is immeasurable. Especially for reading and spelling.
I am not doubting that homework has it's benefits - but I can't see what they are in this case in point. The child is doing it because she knows she has to, no one is checking that she is doing it right, in fact she is continually learning the incorrect answers day after day. I get that teachers don't have oodles of time on their hands, but if no one does check it, then I still am left wondering what is the benefit of it. Try as I might to help her understand how to work out the math, she just didn't understand it, poor kid, and I sort of have this (perhaps misguided) hope that someone might notice and get her some extra support.

Perhaps the real issue is lack of parental involvement? But not every family does have the time to contribute to supporting homework, for whatever reason, right or wrong.