You can have structures were low performing students get tossed out to reduce work or even to gose school numbers.
thats why homeschooling has taken off, at this point public school has degraded to the point where parents believe they can teach their kids better, and honestly its probably true. just through flash cards a reddior was able to get their white kids up to a 5th grade level in reading and math, their kids were age 4 and 3 btw, meaning a 3 year old could probably get a high school degree from an inner city school. Thats how bad it is, another thing that isn't talked about and is why people say the ivy league isn't that hard is that there's an effective ceiling as well because of colleges having to follow from the standards set by the public schools.
Any private school worth their shit will have their kids so far ahead of where they should be that college will be a time of non-stop partying because stuff like affirmative action and school standards mean for the first time in a 19 year old asian or white kids' life they're held to the same standards as blacks and something like pre-calculus was something they already took freshman year of high school. And that whole "expected to work on courses easier than what you did in high school" continues on for the rest of their time in college. Beyond that the fact that a high school is expected to take 5x as long as a community college to teach any level of math classes shows how much of public schooling is a glorified daycare. If any asshole off the street can be taught Calculus well enough to get a college credit in 20% of the time as a high school student with no responsibilities shouldn't you conclude it must be pretty easy?
The problem is if you are one of those sad black kids who was in the honor society in inner city high school, the standards in college are way too tough for you and chances of you dropping out are high and you'll be challenged and be forced to work for your degree while everyone else around you is getting their party on because they're forced into waiting for your people to understand every concept a college professor says.
this isn't even a hot take, plenty of people i know of graduate college at 19 and they don't seem particularly smarter than your average white engineering student. its just that standards are sort of capped and they're above that cap. look at math, Calculus is considered the bare minimum for college graduates while also being something that most private schools expect from your average junior. meaning entire schools have 17 year olds that already have learned more math than we expect out of most college graduates.
Schooling in general isn't that hard if you aren't part of the public school system where every class is diversity unlimited, the other problem is challenging these kids, which public school teachers won't be bothered to devote resources towards doing whereas private schools keep up such a tempo that your average private school bart simpson type would turn into an honors student at your average public school.
This isn't even a modern phenomenon pretty much since the civil rights era its been like this, only the standards have been dropping year after year to the point where just an hour a day of educating your kid can put them on par with a black high school graduate before they're even old enough to use the toilet by themselves.
