[pbmonster]

I don't think so. I think in almost all cases, there's a big difference of going through an entire advanced course on youtube and actually taking the class.

And most of that difference is fighting through the problem sets yourself (in STEM) and actually writing the essays (in the humanities). And feedback loop provided by grading in both cases.

When I learned quantum field theory for the first time, the course had 4 hours of lectures a week. But the problem set for the week took between 8 and 12 hours to solve - as a team (for me, it would have been close to impossible to solve solo, the discussions with peers while working the problem where vital).

I also ended up TA-ing that course the following year, and only after doing that I actually understood the material.

Would it be theoretically possible to learn the material from a youtube lecture and a pirated copy of the textbook? Of course. But I think even the majority of people who already have some formal education in the field would fail to do so.