Re compliance for scaling
It could be true. They sold it to us as a way to teach them. If it’s not teaching them, then they would be wasting the money of taxpayers to do something different. If parents wanted what you describe, or just a babysitter / teacher, then they might still support it. We need honesty, though, so parents can make tradeoffs among various systems.
Also, the capitalists that originally funding and benefited from the public model also send their own kids to schools with different models. Those models consistently work better to produce future professionals, executives, and leaders.
So, the question is: “Do none of the components of those private schools scale in a public model? Or do they have different goals for students of public schools and students of elite schools like their own kids?” Maybe we’re overly paranoid, though.
Re good outcomes
Well, there’s maybe two things going on. Made in God’s image, we’re imbued with free will, emotional motivations, the ability to learn, to adapt, to dream. Even in the hood, some kids I went to school with pushed themselves to do great things. If public school is decent or good, then our own nature will produce some amount of capable people.
The real question is what percentage of people acquire fundamental abilities we want. Also, what percentage is successful? A worrying trend is how most teachers I know are pulling their hair out about how students can’t read, do math, anything. Examples from both people I know in real life and teachers I see online:
“Young people in our college classes are currently reading at a sixth grade level. They don’t understand the materials. I have to re-write or explain them so they can follow along.”
“I get my college students to do a phonics program. It doesn’t get them to a college level. It does usually increase their ability by a year or two level.” (Many seconded that online comment.)
“I hate to say it but they’re just dumb now. If they learn anything, I feel like I accomplished something.”
“My goal is to get them to focus on even one lesson for a few minutes and tell me even one word or character in the lesson. If they do that, we’re making progress.”
Whatever system (and culture) that is doing this on a large scale is not educating people. Our professors should never have to give people Hooked on Phonics on college to get them past sixth grade level. This is so disasterous that ditching it for something else entirely or trying all kinds of local experiments makes a lot of sense.