I guess I'll be the dissenter/mean mom. I think 6th grade is the perfect time for kids to start being held responsible for this stuff. By the time kids are in high school habits are harder to build and break and the consequences are far reaching. Keeping track of grades/assignments/ addressing things with teachers, those are all learned skills. I know very few kids who
want to talk to a teacher. It's really hard to step back sometimes and let your kids suffer the consequences but sometimes that's the best way for them to learn. One of my kids had some really rough semesters in middle school, ( Did the work, didn't turn it in? I still don't get it. ) it was hard and frustrating, we all learned a lot.
Teachers who often have 90+ students are not going to be contacting parents about a missing assignment. We monitor grades, there are consequences, positive and negative. I'll absolutely communicate with teachers or step in when need be, but we expect our kids to attempt to handle things first. ( I'm not talking about things like bullying or difficult teachers, which are in a whole different realm )