I think HR is just ill equipped for technical interviews, but they try to conduct them regardless.
Was denied a position because HR felt my experience "lacked depth" which I still can't understand 3 years later.
Did the same role at a larger company. Had more responsibility than they were giving me. Developed my own tools for job automation. Grew their business from nothing to half a mil a month. Experienced all stages of growth and realized massive success.
After that interview I kept getting technical interviews and getting passed on because I was too senior for the position