To the last point, I believe that, ceteris paribus, competency increases with experience and decreases with time out of the daily exercise of those skills.

Of course everyone tries to evaluate absolute competency (ceteris non paribus) in an interview. I’m not suggesting that anyone stop doing that. I am stating a belief that experience is positively correlated and perhaps a necessary precondition of competency. If that's the case, considering experience as a component of the overall evaluation is indicated.