Precisely.
Another aspect of “why they are where they are” is consanguinity and the attendant IQ and health issues. No one likes to talk about it, but if you dig around, the scientific literature is out there. All those jokes about marrying cousins in Appalachia? The Muslim/Arab world makes them look like rank amateurs. Tribalism and arranged marriages to near relatives are not A Good Thing.
You know, that really isn’t mentioned at all. In fact it’s so rarely brought up, that I even didn’t remember it until you mentioned it.
That is a pretty serious issue.