The point is, the real world still needs you to be productive in different things. You'd better have that first, get some real world experience and then expand your career horizontally by getting into these fields. I think the mistake is that some people have been pursuing these career in a vacuum and also took a lot of debt while doing it.
So while they might have had an interesting experience while at college, they are not of much use in the outside world.
In what way is it invaluable?
Have a broader awareness of things, of other arts, of history, of other crafts must make you better in your core competence in some way I must imagine. For a computer programmer at Apple who is going to be designing a macbook, it's probably better that he have some inkling of what that machine's enduser would be doing with it. Is he going to be making music? Spending a lot of time watching political videos on youtube? Having insight into people, into other crafts will let him make a better machine.
Skills transfer across domains all around, sometimes wholesale and other times in small subtle ways. I was always stunned, for example, in reading Einstein's essays on subjects others than physics. His writings on politics, music, religion etc. reveal a man of tender awareness and care. Would he have gone to develop the theory of relativity if he had not read works of Immanuel Kant? Leonardo da Vinci, Donald Knuth, Archimedes, the examples are aplenty for accomplished figures who had their hand in many jars.
I think the benefits of a liberal arts education are probably worth everything its proponents say. Having a well rounded education, which exposes one to not just new ideas but an openness to new ways of thinking, is invaluable. I’ve hobbled together what I can from earnest interest (and some free courses from universities which opened up their lectures), and I’ve grown a lot from that. I hesitate to imagine how much more I’d have benefited from college being described not as a vehicle for future success but as a part of becoming a person in a world that only gets more complex—with age, responsibility, and time in a society.
I lucked out on the career front, but a more formal and broad education is something I really regret not pursuing at the time it most fit my life trajectory. And I think everyone benefits from that spirit of education continuing to exist.