Glad to hear parents are altering the social contract, and hopefully for good. Let people take their kids out and bring their kids in anytime of the year. Schools need to adapt instead.

Attendance isn't fundamentally the problem. Self-paced learning is what's needed here. It should be okay to have students at varying stages of learning the material.

Teachers should be careful about wasting class time with lectures. Flipped classroom model or similar is probably the way to go - lectures in video watched at home, class is for practice/homework/support.