(note that one of the best ways to learn transferable skills is through 3-4 years embedded in discipline or disciplines-specific knowledge! But even if the subject-specific knowledge gets you your first job, it’s the transferable skills that get you a career.
So much this. We don't need to teach kids how to do a job, we need to teach them how to learn things well, how to apply what they know about one thing to something else, how to communicate ideas in both directions how to adapt their ideas and skills.
And I mean I say this as a subject-specific educator. Most of my students won't end up working in the field I teach them. I hope I can still teach them some useful skills!
Psychology and geography are my go-to recommendations for the broadest possible range of skills acquisition. straddle the humanities/sciences divide AND the qualitative/quantitative!