like we admire the great wall of China
Well, we do not admire the Great Wall of China for its effectiveness...
But at its time of creation it shew the same effectiveness that one or the other Roman
border fortifications shew.
In a way it looks similar to todays Israeli or US walls and border control.
One aspect is to show the inside as civlized and "superior" outside as barbarism.
( and both try to actively squeeze that barbarism to the surface by their own actions
to have something for finger pointing "those barbaric people on the outside, be happy
you live on the inside".)
Strange book around from one Robert Anson Heinlein: "Revolt in 2100"
US is a walled of religious dictatorship.
Big difference in the beginning Chineese and Roman actually were more civilized
and had much better infrastructure. not the case today.