However, lectures allow you to use TA's to more cheaply expand class sizes and might make it possible at the undergrad level.
I'm not saying remove the human element entirely, but there's a lot of low hanging fruit in education to consider where technological automation can help improve the productivity of educators.
Check out how Georgia Institute of Technology is offering a real CS Master's Degree for a fraction of the cost using similar stuff: https://www.omscs.gatech.edu/
This x1000. With all the improvement in educational technology, it's weird that the gold standard of elite education apparently remains the lecture.
I am reminded of the quote: College is a place where a professor’s lecture notes go straight to the students’ lecture notes, without passing through the brains of either.
Part of the issue is that college-as-elite-networking-venue needs to remain scarce, by definition, if it is to retain its value. If everyone can "go to Harvard" (through online delivery, enhanced ed-tech, automation, etc) then the scarcity is lessened. When you go to an elite college, you don't just get an education, you get association with a brand that, you hope, retains and increases in value.
I'd like to point out that there's also plenty of utterly crappy educational technology that only exists to nickel and dime students for licenses. See MyMathLab.
What makes one a good prof/teacher/lecturer for a given department, subject matter or set of students may not make one a good prof/teacher/lecturer for a different department, subject matter or set of students.
The quality of an instructor as a prof/teacher/lecturer for a given department, subject matter or set of students implies nothing about the their quality in any of those attributes for the same setting or the same attribute if the department, subject matter or set of students changes.
I recall having a discussion with another student who had very similar abilities and interests. We agreed about the quality of the profs we had in common except for one where one of us thought he was a great teacher and lecturer but terrible at the rest of being a prof and the other thought he did a great job as a prof but was a terrible teacher/lecturer.
Really face time with a professor is not directly the huge cost you might think. Class participation and helping students during office hours don't scale very well. On top of that it's much simpler to cheat in an online only environment.
Honestly, I think High school is probably a better place for this kind of automation. Setting up a rotation where you have say both a small and double sized classroom seems very possible.
In the UK a professor might take 3-6 lectures and 1-3 classes a week, and they're often staffed by masters students.
It might be possible to nominally get that number but only if your hiding other costs.
Does that mean they could be paying those professors $300,000?
Further, just having a teacher without a classroom is not going to get you very far. Still, assuming the average student pays 1/2 that much per year they can probably cut the costs significantly.