My recollection of the research is the HW has little to no benefit till middle school or so, and even then, it's only for things like math and possibly science--subjects where concrete practice increases mastery.

I wouldn't mind if DD had a sheet or two of math and was assigned to read nightly (though she does that anyway). I actually think the special projects they do are cool, so those are fine too. But the rest of it is busywork and drudgery. Part of the reason DD does not play an instrument is that she and I both know that adding 30 minutes of practice time would eat into the little bit of free time she has left after school (she does belong to some clubs she enjoys). She's 9. That's awful.