College never helped you teach!
Multiple things and probably could be a book...
It was elite simply to be accepted and go; even if they dropped out later. Better, smarter, more innovative desirable workers who are generally less gullible. School helped make them but a large part was the selective nature of the process.
An adult who wants to learn who made it that far should already know how to learn well enough that no learning expertise is required! This is why there never was training in hand-holding education. One simply has to KNOW their topic to accelerate the student and the institution there to facilitate. A masters or PhD is more of the same. It is about training the mind; it could take a lifetime to get as far as an intellectual elite, or they could try to convey their secrets and wisdom. Some of which is not clearly understood or documented. still.
The PAST was for the elite. Elite was good; while now it's only good for wealth, intellectual elitism is attacked by the establishment because it's a real danger to them and their tiny little thiefdumbs they strive for as their legacy. I WANT an elite doctor...don't you? (extreme cases exist everywhere, but in this age, nuance is dead.)
Complex modern societies, realized free universal mandatory public education was necessary! High school wasn't necessary until it was. Think about that. Now we've progressed to where 2 years of college is necessary. Trade school included. You can't even be a plumber without training; it's not like the week of fast food training... and the difficulty almost entirely relates to pay.
High school needs to replace the first 2 years of college. But also, there is a war on education going on since Nixon started it. I knew people who were actively trying to destroy public education in the USA and figured we are so great we can handle the damage from some generations being harmed in the transition. These people weren't college educated by the way, also quite ignorant and not curious - but the marketing man I knew worked for the GOP on it. He stated the plan. American High School needs fundamental changes but it can't even perform at what it used to do; and the democracy and government are slowly collapsing. Repair is impossible, forget adaptation. There is no civics, the primary reason for socialized education that some of the founders argued was necessary was an uneducated uninformed society is not competent enough to govern itself. Absolutely, we're more educated, but relatively, we're incompetent in the USA and most of humanity can see that.
Colleges and technology have degraded. Aside from the problem that it is no longer elite learners, we've been treating the masses as customers. Business metaphors all over; and far too many business majors probably is part of it. Education is NOT a business anymore than electricity is water (the metaphor fits in simplistic ways that become a hindrance later.) Lectures a century ago were more interactive; active listeners existed back then. When nobody utilizes the expert, then they may as well watch a recording or a student presentation of the textbook, or an AI. Powerpoint has done immeasurable harm to education... it may have helped business people with their toxic meetings... When all you have crap education you can't tell any difference and online learning should look comparable as should AI, certifications, etc. The wealthy will still get the better education if they buy into the right schools. The masses will get cheap AI bots; engineered to job training and actual indoctrination.
A graduate is supposed to be able to think and learn on their feet. Part of that skill development is weening them of baby sitting teachers! Yes, it would be best if we specifically focused on how to learn and we do not. How do I, an expert, teach myself? what is best for doing that? The kids should be learning study habits before this point... oh, and not memorizing processes. Science education is largely science history memorization. The scientific method is not applied enough in practice. My science lab was doing measurements in a pre-configured experiment that mirrored some homework problems. What you learned was how to fudge the errors of the experiment to fit into the word problems. HOW you devise the experiment never ever was alluded to. Eventually, if you go masters etc, then i suppose it gets to you by osmosis?
ENGLISH. YES! They need to be able to communicate. A well funded school can handle it if the TAs are good and plentiful. The TAs learn much from their experience... probably grad students. If managed well it's not cheap and it's a good model where English might not be needed by the expert.
Look into the tradition of Oxford. Some bad stuff but some results in them being elite even today. Just flunking out is still something people brag about (but present as how many years they attended.)
Textbooks are valuable. Most everything can be learned from those; if you have discipline and self-learning skills. It goes faster with help... a coach. or assistant coach. sport is a far better metaphor than business. A full time student spends a FULL JOB 40+ hours per week on study, not passive lecture watching. We've come to expect lecture to replace the textbook; it's supposed to clarify, highlight, supplement, and reiterate (repetition is needed for retention.)
What the customers want is wrong. The inmates have too much control over the asylum and we're all slowly going mad.