Of course educators rarely base their instruction methods on research, they simply do what is easiest and pleases the parents and administrators.
Back when I taught school I did not assign homework often - maybe once every couple of weeks. Why not? Because I did my best to make use of classroom time with the students. We didn't use a 'Smart Board' (I call them 'dumb' boards). We drilled on paper and worksheets. I did not use exclusively the worksheets provided with the textbook, instead I created my own worksheets. We focused on one topic at a time and the students mastered the topic of the week. No spiral approach!
Homework is given for a few reasons. One reason is many parents expect it. Often parents will equate lots of homework with a tough, hard, good teacher. I usually find the opposite to be true; the teachers giving the most homework are the laziest and least productive. And these same teachers either have kids check the homework or never closely examine the assignments. The problem here is the teacher may not be stopping and correcting bad habits.
Teachers feel pressured to give homework from their administrators or from co-workers. "Mrs. Smith, why are you not giving homework like the rest of us?" Teachers will also wonder if the parents will view them as poor instructors if they don't give homework.
Too much classroom time is spent with non-instruction issues. Discipline (behavior), dress code enforcement, bullying prevention, mandatory paperwork, , IEPs, etc. take away from instruction time. The ideal teacher will train the student to enter the room, keep their mouth closed and take their seat, then start the assignment on the
I nearly caused a riot back in my middle school teaching days when I suggested the principal remove all of the teachers' desk chairs from the classrooms. I never cared for the teacher who placed his/her desk at the back of the classroom and stared at the kids' backs while they did busy work.
If you have a kid in public school, they are in the government's care from 8:30 AM until 4 PM. I think that's enough. When the kids get home from school, that's family time - not more government-controlled time while they do required homework for three hours a day.
But does homework enforce the day's lesson? Maybe, if the parent is there to help and review when a student has not mastered a topic. If the kid learned the topic in school does doing another 50 problems at home make the student 110% educated? No. They either know it or they don't know it. If they don't, then the parent needs to work on that topic until it is learned, because the class is moving on. If a teacher is teaching long division and your kid correctly calculates all the problems in class (maybe a worksheet with 20 problems) then why give this kid another 50 problems that night? However, if your kid failed to properly calculate all the problems in class, then he/she needs to continue to practice this skill (in class and at home) until perfected.
So, do you let the kids come home form school, fire up the i-pad, and chill the until the next morning? Not hardly. How about reviewing with the child the topics discussed in school? Then some independent reading and maybe some writing practice. Have them write thank-you letters, help plan meals, work on a budget for the family, maybe even turn a few wrenches in the garage.
Beware the Homework Queens (and Kings) at your kid's school.