All of which is usually covered by 8th grade in the US.

HS is a waste for most people attending.

1) The baseline is extremely low, and getting lower by the year

I will take math as an example. High school, at the best possible setting, leaves you knowing single variable calculus.

Is this enough? no, it's nearly zero. To be able to understand anything about math in the modern age, you have to know :

- Formal logic

- Linear Algebra and Differential Equations at 4x courses or more level

- Probability and statistics, 2 or 3 courses.

So all in all, in order to even think intelligently about a field like math, in order to have any chance at all of even comprehending the slightest inkling of what all those scientists and engineers and ML practitioners who impact your life massively even do, you have to know easily 10x of what high school, in the best possible scenario, teaches you.

Then one year passes, science, math and engineering get more complex, and high school curriculum and budgets get lower and lower, and the race to the bottom continues.

You can repeat this exercise for any subject : Ask a specialist what's the bare, absolute minimum for anyone to think or reason effectively about their subject, compare their answer to the K12 curricula for that subject, and laugh at the sheer mismatch of the two.

2) The baseline is redundant and wasteful

The sheer waste is mind boggling, all of my K12 education could be easily compressed in 6 years of study. Lessons are repeated over and over again each year, irrelevant subjects like the agricultural policy of Brazil and Nigeria are stuffed in overweight geography curriculums for no apparent reason (my country is neither of those 2), the English language's way of annotating verbs with tenses is rehashed for the 7th time this year.

There is no concept of opportunity cost, there is no awareness of a notion of "What could I teach this kid this year instead of yet another rehashing of the names of the world's most popular rivers and mountains?".

3) The baseline is low quality, low relevance and low impact

Programming is memorizing visual basic's or php's basic syntax, math is learning a formula and repeatedly applying it over and over again to questions with parameters varied, biology is memorizing the reasons of why various phenomena happen.

It's not only that what gets teached is a pathetically small subset of what needs to be teached, and not only that it's teached in 2x the time needed with metric tons of mindless repetition and rehashing. It's that even this small subset that is teached and re-teached, is teached in the most boring, unmemorable, uninspiring, useless and actively harmful way possible.

It's not a good baseline, people leave it not knowing a single worthwhile thing about anything or - even worse - actively thinking those subjects are useless pontifications and navel-gazing. It does an awful lot of harm and virtually 0 good, when you divide by the time and resources it consume .