IMHO the common practice of homework is maybe not completely wrong but executed incredibly badly. I remember one time where I was with a friend doing homework together. It was about writing a text. We were so incredibly bad at it, the texts were full of repetitions and missing the important information. How should a 12 year old know how to brush up his writing skills outside of school anyway? I ended up skipping most of my homework the rest of my school time. (This worked surprisingly well for most subjects and teachers.) Going to university was such a breeze in contrast. Clear instructions, self-contained lectures, references are provided so it's possible to drill into a topic either alone or together with others...

To me school is mostly about teachers checking on students instead of them actually explaining things. Once I was on a summer school in the Netherlands during university and I remember one of the professors saying that during the first 2 semesters they need the students to unlearn destructive behaviours from school. E.g. admitting when they don't know something and to ask. I'm from Germany but to me it seems like a problem occurring in many countries.