> something is going on

Many things could be going on. You should propose a concrete explanation instead of some vague "something is going on" placeholder which could uncharitably be described as dog-whistling.

For example, consider that leaving one's country is difficult and, so, the distribution is skewed towards individuals with higher skill and talent.

I'm not saying that is the only effect at play here. My point is there are many effects and a lazy "something is going on" statement does nothing to understand that complexity.