I don't know who started the incredibly inaccurate naming of personal skills as the "soft" skills. They are harder skills to achieve, apply and master than the other so-called "hard skills."
What we call hard skills are technical skills. They are mechanically learned and applied. They don't require any particularly mindsets because they are intrinsically impersonal. Personal skills which are actually the hard skills are not mechanical because they require new mindsets along with skillets.
The real hard skills include: working from good questions, presence, agile organization, connecting conversations, growing ideas, learning from experience, peer2peer learning, defining why, personal brand management, facilitating collaboration, sense making and entrepreneurship.
We now have evidence that what makes an individual or team high performing is the constellation of hard skills they have developed and engage.