I noticed a new interesting comment that give even more insight about Imperial nature, and why this type of government and 'way of life' way chosen in the first place to last 10k year here instead of the 'enlightenment' (also recommend check previous comment for more idea)
https://forums.sufficientvelocity.com/threads/the-galaxy-is-flood-not-food.123284/page-74?post=30794714#post-30794714
https://forums.sufficientvelocity.com/threads/the-galaxy-is-flood-not-food.123284/page-74?post=30794714#post-30794714