In Czech Wikipedia, 8.3% of new users visit a page in the Help namespace as their first action after account creation. This number is higher than in Korean Wikipedia, but it is currently difficult to tell how much higher, since Korean help pages are incorporated into the Wikipedia namespace
It's not uncommon to see on help / documentation pages for other websites something like "Did you find this page helpful?" with a "yes" or "no"; while I'm uncertain of how well that would work for rating help pages on Wikipedia, it might be worth considering as a way to gather some insight into whether the users visiting the help pages find that their questions are answered.