They missed nothing but a load of worthless busy work.
And thereby your kids missed the most important lessons of all.
Let me qualify that just a bit though...
If the teachers give all the kids so much homework that they have no free time at all, that’s not good. If the teachers give enough work, tailored to the students, that all have to work pretty hard for 1-2 hours, M-Th. evenings, I approve.
If the teacher(s) are assigning work that takes the students over 2 hrs. every evening to complete, the parent should talk to the teacher(s).