Interpretation of the Hirsch index, help

I know that among the community on this wonderful forum there are practicing scientists from different fields. I would like to ask you to explain to me whether the Hirsch index is some kind of determining indicator. For example, if Christof Koch has a higher Hirsch index than William Newsom or Sir John Eccles, does it mean that he is a better scientist? Or does it just mean that his works are cited more and are more often referenced? As far as I know, there are unpleasant incidents in the scientific community related to plagiarism and artificial increase in citation. Is the Hirsch index really a determining indicator in assessing a scientist? Of course, I understand that comparing the index of scientists from different fields is stupid and incorrect. Thank you.