Why shouldn't children take days off from school?

There is a lyric in the song "KANPAI Year!!" by Snow Man that goes like this:
"Adults and children are both doing their best! Working hard, working hard, doing our best! Good job to you and to me!"

Hearing this, I felt a strong sense of empathy, thinking, "That's right. Children are working hard, too," and at the same time, a question I had always held in the back of my mind suddenly surfaced and grew larger.

That question is, "Why can't children freely take days off from school?" When I was a child, I went to school as a matter of course and never had such a question, but after having children and raising them while working, this question began to arise.

I started thinking about it especially after my child entered elementary school.

Sometimes, we go out as a family on weekends. As long as work permits, parents can adjust their schedules and use paid leave to take a day off after the weekend, like on a Monday. We can rest our bodies.

But children have to go to school even at times like that.
When my daughter was in nursery school, I would let her take days off with us, but once she reached elementary school, it seemed the children felt that "taking a day off when you aren't sick is skipping school." She would worry that if she took a day off, she would be asked why, and told "You shouldn't do that," so she would go without taking any days off.

By middle school, she started worrying about "falling behind in class" and would push herself to go. And there is this pressure—whether it's true or just a superstition—that having too many absences will affect her school records, so the option of "taking a day off" simply doesn't exist.

People might say, "You're young, so you have the stamina," and that may be true, but if you are doing club activities every day, including weekends without a break, and then go out with your family on the rare day off... even a young person would get tired, right?

Seeing my daughter like that, I wondered once again why children shouldn't be allowed to take days off from school.

If schools provided about 20 days of "special leave" per year, families could go out on weekdays, and children could rest their bodies after the trip and return to school feeling refreshed the next day.
Tourist spots would also benefit from having visitors spread out. Wouldn't that be a win-win?

As for falling behind in class, in this day and age, if classes were recorded and made available to watch at any time, students could catch up by watching the recordings while relaxing at home.
I worry it might increase the workload for teachers, but with tools like Zoom, it's just one button to record. If they just put the data in a shared box and said, "Feel free to watch it," it wouldn't be that much trouble, would it?

While writing this, I thought that if classes were streamed, we wouldn't even need class observation days, which might make things easier for teachers. They wouldn't have to prepare special lessons for those observation days.

Thinking about all this, I felt that there are probably many "musts" and "must-nots" in society that are just continuing out of inertia.