I agree - homework did nothing for me when I was in school. I could always ace the tests but teachers insisted homework "because" - never made sense and was a constant source of friction. Jackasses.
Homework is totally different for me in university compared to high school. Math in high school was easy. The homework just felt like a waste of time: repeatedly applying what you learned from one example.
In university, homework is everything. If all you do is attend the lectures, you will fail the midterm and final. In order to do well in the course you need to do all the homework which really pushes you to learn. The examples given in lecture are completely trivial compared to the homework problems which can often take hours to solve.
“Enrichment activities” would actually be useful if the content was actually enriched. Advanced students would get a lot more out of school if they were given work that was genuinely challenging for them and took a long time to figure out.
My first collegiate math class, the teacher came in and asked the class, "do you know how to get an A in this class, two hours of math homework a night". I followed this advice and bam, A. Despite the fact that this math class was much harder than anything I did in high school and I was always a B+ math student.
The next semester I followed this advice again but let myself slip a few weeks and bam B+. The next semester I strictly spent the time again, bam, A.
Through upper class years my diligence in school was consistent but I sometimes had to focus on programming over math. I noticed a near perfect correlation between the time I spent on out of class work and my performance.
My experience was similar - in highschool, the class is divided into two parts, the 'lesson' bit where the teacher explains something, then the 'practice' bit where the class tries use the information from the first half to solve some problems. In university, the entire lecture is the 'lesson' bit and the assigned homework is the 'practice' bit.
I made that complaint--as a flippant remark in class--to a high school statistics teacher once so he assigned me the task of writing my own final exam rather than taking a final exam, and gave everybody else the option of taking my exam or his. (Nobody took mine.)
My grades weren't that great (classic B student) and I doubt I had better mastery of the material than the more studious ones in class. But writing the exam was both fun and challenging--I definitely had improved mastery afterward, as well as a newfound appreciation for his job. He gave me a B+, though, out of fairness as I had several days to write the exam, open book. Which was fine by me.
I didn’t like homework that much because there was so much of it. But if I look back, I probably learned the most doing homework. I was alone, concentrating better and having to figure out how to get the homework done.
In college homework was the workhorse of my acquired knowledge.
I think it is quite clear that being inately smart could cause quite a setback as one thinks they don’t need to work hard and winging it would do it. It turns into a bad habit and eventually one falls behind and stays there.