That's been the story at my kids' old school.
Certain students who are prone to allergy symptoms and colds have been missing tons of class time with the "stay home/get tested/return 48 hours later" drill. And the school has a policy that if you are enrolled in-person and have to be at home, you can't switch to remote. You are locked in and have to sit at home for as long as it takes doing nothing at all. Can't bring any books home either.
The teachers I have talked to have resigned themselves to this basically being a lost school year for most kids. Very little forward progress and the kids who were behind are even further behind now.
So glad we were able to homeschool this year. Our kids have been flourishing. I really recommend it for any families that can manage it.