Not true in the case of the US, which famously adopted a culture of universal literacy earlier than the rest of the world. By the mid-19th century, literacy rates among whites were not much different than they are today. It is one of the bright spots of American history; they took literacy very seriously for complicated historical reasons. Their book consumption per capita was also the highest in the world by a very large margin back in those days, which lends evidence.

It may or may not be relevant to your point, but at least in the US the idea that the average person was illiterate is ahistorical. They were the best read population in the world 150 years ago, and took some pride in that.

Schooling didn’t fix all that. There have been major advances throughout society in every area: medicine, nutrition, sanitation, manufacturing, electricity, refrigeration, printing, computing, telecommunications… the list goes on and on and on. Some of these things contributed major improvements to the average person.

Advances in medicine and nutrition, for example, contributed to sharp declines in early childhood mortality and morbidity. Advances in reproductive health care (along with everything else) led to huge declines in birth rates. Smaller families have more resources and attention available for each child.

Other advances had less of an impact but still add up when combined. Widespread access to refrigeration improved nutrition and reduced spoilage, allowing increased consumption of meat. More meat means taller, stronger, healthier children.

On the other hand, schooling hasn’t improved all that much in 150 years. You can find lots of writing samples and old exams for schools from back then. The bigger difference is that children stay in school much longer and have less need to rapidly enter the workforce in order to support the family. This last factor is a product of many of the advances listed above.

Children are required to be there. The school has to provide them with all manner of opportunities.

On the flip side, the school can't expect anything from the kids other than attendance. They don't really get to expect a certain level of behavior or performance. They can't relegate the bad actors (behavior or performance) away from those who wish to participate fully. Everyone has to be mixed together.

So you give a certain vocal minority that don't care about the education a heckler's veto. They are regularly disruptive and can't be removed.

Nobody has a solution for actually improving that group of student, but there are enough people involved in public education that demand these students be included in the process that they are trying to wreck.

> schooling fixed all that

Not globalization, industrialization, and urbanization?

Illiterate, yes, but likely better at other skills like milking cows and knowing which plants in the forest were edible. Less connected to the global world and culture, yes, but more connected to the hyper local environment around them. I don't know if the schooling "fixed" anything, it just created a new, national or global template for what a human being should be like.

In what way do you mean this?

Schooling has fixed all that, and still works just fine. Just not in America, because that country is rapidly self-destructing. Schooling is still working fine in the rest of the world.

Because an educated populace is harder for the ultrarich to control and abuse, because an educated populace with free time can revolt against those in power, and because as a consequence of those two things ultrarich conservatives have consolidated ownership of media and used it to defund education and convince the population that funding education is bad.