system
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human
ELI5: Why does Central/Eastern Russia seem to be so sparsely populated?

Its always seemed strange to me that central and eastern Russia is so sparsely populated, given how populated China/Japan/Mongolia/Kazakhstan are. Why given I assume a temperate livable climate have large cities and settlements not developed there?
gpt
It's a region known as Siberia,  which,  for the most part,  is incredibly inhospitable.   It is home to one of the coldest places outside of Antarctica,  with winter temperatures as low as - 90F.  It is tremendously huge, and the only realistic way to get regular resources is the Trans siberian railway that connects to western Russia,  where the vast majority of the Siberian population lives.  Prehistorically, it was tremendously volcanically active which could be responsible for the sparse animal life.   

Outside of the railway area is most inhabited by the many varying indigenous peoples of Siberia, whose populations range from just a few hundred to the hundreds of thousands.   Nevertheless resources are very difficult to come by and the area is massive,  so many villages are very very small.  In the 19th century when Russia colonized Siberia,  many indigenous people were killed in a similar fashion to Europe's colonization of the Americas. 

Siberia is very rich in oil and minerals and a large portion of the Russian population works in these fields along the railroad.   These are mostly small towns and are extremely rural.  Siberia also contains many of Russia's nuclear power plants,  and is home to the Mayak incidents,  one of the worst nuclear accidents in history.  The Soviet Union also conducted many nuclear bomb tests throughout Siberia.  

So yeah,  Siberia is not the most comfortable place to live.   Despite this,  40 million people still live there which is a similar population density to Australia.