Hussar
Legend
How do you expect a society to exist for 1,000 years without changing. Heck the Constitution of the USA did not even last 2 years before being changed.
Because it can’t change. It can’t afford to change. Any change can potentially fail and over that long some changes will fail.
And failure in this sort of system is catastrophic. It cannot be robust enough to allow for complete rewriting of society. Even partial change has to be avoided.