[asciident]

I'm not sure I agree. Everyone's situation in a PhD is different enough that the only general concepts you could teach would be high level and useless. Personal finance classes in high school are filled with junk like "make sure to spend less than you earn" and "here's how you balance a checkbook" and "never forget to pay your bills". For group work, the workshops I've taken for it talk about "listen before speaking", "repeat what the other person said so you are sure to understand it". Sure they're kind of useful, but mostly not.

[ta1234567890]

You are saying that you've had bad experiences with courses trying to teach those things. Those things might not be easy to teach. But that doesn't mean they are useless or that they shouldn't be taught. To me, it means the methods of teaching those things, in the workshops you took, should be improved.

[asciident]

I think it's likely that there's no way to teach those courses that is useful to a broad population. It's just such a subjective thing, like imagine teaching a course on "how to be happy". Even someone trying really hard may have limited impact.