But "mental health" also implies specific value judgements which are relative to the dominant ideology of a society or civilization. It's these value judgements that determine how the "averages" or the data in general, is interpreted.

For example, if you lived in the middle ages and you were a radical atheist, no doubt that under that system of education and propaganda, you would have been deemed by that society to be "mentally ill" (or similar contemporary equivalent).

The charge of "mental illness" or psychological pathology in general, has throughout history been weaponized to isolate and/or suppress politically incorrect or heretical ideas that run totally counter to the prevailing world-views.