That's not totally true. The way we have lived since the 1950s has made a lot of difference. Even where people have lived for a long time, highways and major roads since 1950 in terms of danger are a step change (or two) compared to earlier roads and have essentially walled off areas from wildlife traveling between them.

The thing is a lot of these rural areas were farms before 1950 or if we got back further before even the Meji Restoration in Japan.

It's actually more of a recent phenomenon that a lot these small villages and towns now becoming basically vacant in Japan.

People have been in Japan for many thousands of years at this point.