the quality of having technical expertise is called?

What is the quality of having technical expertise? I tried to use the word “knowledge” but not correct.

I searched over the net and found that

Technical skills, also known as hard skills, are qualities acquired by using and gaining expertise in performing physical or digital tasks.

and definition of hard skills as per investopedia is

Hard skills are learned abilities acquired and enhanced through practice, repetition, and education. Hard skills are important because they increase employee productivity and efficiency and subsequently improve employee satisfaction.

Is it right to say the quality of having technical expertise is hard skills? or any better terminology?

Context: I was referring to a story of an technical expert, where the complete shut down of a company (for example complete Electricity or machinery shut down)happened and nobody can fix and they asked for external help. the expert fixed the issue by doing a simple task ( say changing just fuse) and charged heavily and when asked why he charged he mentioned to fix it $1 and to know what to fix it $99

Think of a quality which a successful person possesses.

1. creativity
2. resilience
3. knowledge – Here knowledge is not the quality of a successful person as per my teacher. But having technical expertise makes a person successful. I want to have the term for this third quality.