The higher one advanced, the greater the difficulty of ascension.
Only by finding ways to grow stronger outside of dungeon rewards, such as cultivating techniques or receiving support from one's nation, could one continue to raise their rank.
However, for most civilizations, becoming stronger through methods outside of dungeon rewards was simply not realistic.
The Purple Profound Civilization was a clear example of this.
They had no national rewards, and the effects of cultivating techniques were extremely poor. They could not even handle Difficult Dungeons properly. The vast majority of their people were stuck at the third order, with only a handful reaching the fourth order, and not a single fifth order expert.
