Most of history was a very different place before advancements outright snapped assumptions in half. Before most of the population was farm laborers and societal hierarchical complexity and knowledge was limited by this.
Industrialization was raising pollution and standards of living and making it clear that a lack of education wasn't a healthy option - although partially driven by wrong reasons - paranoid anticatholicism that ignores basically all of European history of how much influence the church /actually/ has over secular power.
Even post WW2 industrialization the population was still at a high school diploma as an actual advantage but "optional".
We need more informed not less. Problematically the populace also needs more critical thinking and self guidance while there are many unhealthy attitudes towards learning.
Compared to nothing on those who try to fill the void? Hell yes. Look at those raised in literal cults for example or among fundamentalists. Now I know these are tripping hazards for ants low goal posts but for once "it could be worse" is pertinent. An education can provide the prerequisites to evaluate and enable it.
Often they do try to put their bullshit in it but their hamhandedness in practice often backfires by adolescence - especially with their own twisted priorities and misrule related discontent.
Presumably most people who “find their own way” would not drop out of high school, and their experience would be better — because there would be no one present who was only attending because the law mandates that they do so.
Reading and writing are unnecessary for much of the population given the progress in speech to text and text to speech algorithms. We can go straight to learning how to express ideas in speech and learning how to locate, access and understand information.
And calculators have rendered arithmetic unnecessary for some time. The focus should be on how to use calculation for financial and technical purposes.
I had a history class in school? No period sticks out even remotely comparable to modernity by any metric: violent deaths per capita, general life expectancy, education, leisure time available..
If some future historian were to look at the 20th century he would observe a huge amount of violence and death dwarfing anything that came before. I am not certain the modern age is altogether superior.