Widely distributed ethnic groups are rather rare - people have a tendency to stay put (with some spectacular exceptions during some periods, obviously)...
True. Which is of course another way the Jews are unique.
The Japanese are probably almost identical genetically to the Japanese of 2000 years ago, since nobody invaded Japan. (Except the Mongols, and it didn’t work out well for them.)
The Chinese probably much less so.
But the Jews were one of many small peoples around the eastern end of the Med. Where are the Edomites, Moabites and Ammonites? Where are the Arameans and Chaldeans?
They’re gone, but the Jews are still here. To my mind, anyway, this is pretty much proof of something unique about them.
There are still Egyptians in Egypt and Greeks in Greece, but they don’t have much of anything in common with those who lived in those lands 3000 or 5000 years ago. So are they still “the same people” in the way the Jews and (possibly) the Chinese are?