system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why are most of the oldest companies in the world from Japan?
gpt
The answers about no civil upheaval are rubbish. There were at least three rebellions/civil wars around the turn of the 20th century. Also there was this scuffle known as World War II that devastated the Japanese Home Islands.  


The real reasons why Japan has so many old companies are because they heavily emphasise tradition and continuity and the widespread practice of adult adoptions. The owners of the companies would marry their daughters to a suitable heir and adopt that person into the family. With this continuity in place, you're seeing the small handful of survivors that have managed to make all the way to this age. You're not seeing the tons of failed businesses.  


If you look at the list, most of them are hotels offering a traditional experience, some make traditional confectionary and the rest produce goods related to temples and religion (the two construction companies specialised in building temples, good business in a place subjected to frequent disasters). All heavily emphasise tradition and the age is a plus. You can see this too in Germany where 9 of the 11 oldest are related to alcohol where tradition is prized.