Someone who does homework meant to reinforce or review what was learned in class that day is benefiting from it. However, when the homework given is not related to what was learned or is excessive or needs to be done by the parents, then this is not going to be beneficial.
Homework is essential to the education system. It is a chance for students to see and apply what they have learned in school. It also lets teachers know you have grasped the material. Too much homework is not good but everyone needs some level of homework most days of the week.
Homework does help students review what they did learn in class. It gives them a chance to go over it again later in the day to help get it in your memory, than it will also help the student see where they are struggling and what they are good at.
When homework is given in reasonable amounts, yes, it does help to review what was studied in class and better memorize it. However, when students are loaded with hours and hours of homework, it becomes a big burden and big stress, nothing else. I remember trying to memorize tons of stuff, struggling with it, and feeling overwhelmed as a kid.
Homework does not help students review what they did/learn in class. Homework is just another added pressure on the education of students. The amount of homework given to students usually keep them focused on school way into the night. I do not think it benefits a student to have to do three to four hours of work once the school day ends.