Reading
Writing
Arithmetic
These are all easy to teach. Somehow, the government schools have found a way to screw them all up. I worked at a Teachers college in the 1990s. I think it’s all deliberate. They don’t train teachers to teach anything. They train teachers to push an ideology.
And when the public notices how poorly educated the children are, that just becomes an excuse to funnel more money into the school system. Failure is rewarded. Therefore the educators fail. A lot.
There are very few consequences for failure. School systems don’t go out of business.