I don't think most people really understand the impact of how our nation responded to COVID wrt education. IMO, it is as if the vast majority skipped that year and all of the fundamental building blocks for so many classes.
I read somewhere it had a very disproportionate impact on kids in their first year of school at any level - so K, 6, 9. This year’s sophomores were in 6th grade when school didn’t go back in the fall.
My daughter was in 5th and they opened the elementary school in Oct with half the kids - because the others chose to stay online. The middle school opened in person in April. One year difference in missing 6 months of in person learning. When my daughter started 6th the teachers commented it was like having two 6th grade classes at the same time.