Lol using tendencies to make predictions is common practice. It is absolutely not useless. Its something to look out for albeit not be sure of.
Personal anecdotes lmao. Do you truly wanna act like this is not supported by data? Once again not a rule of law but a tendency applying to a significant share of minority populations in varying degrees:
There is a very clear tendency of minority populations fostering communities with each other in foreign countries. Like their own churches, sporting clubs, restaurants/bars, little markets delivering home country goods whole city districts sometimes even. All of these places are typical places for them to socalize specifically with each other.
This is reflected in social circles too. You can often see a clear bias towards their own in their friend circles compared to what the local distribution actually looks like. A minority might consitute only 2 % of the local population but the friend circle could be closer to 30-50%.
Now there might be some 5 likes post or 300 views interview hidden of something giving information on his own case that is more valuable than these tendencies but this is NOT just personal anecdotes.