Originally, the significance of the Thousand Mountain Ancient Realm was not in exploration, nor in the massive amount of materials deliberately created. The kings all knew that this was a king-level world, so there must be great opportunities.
Whether it was the humans or the kings of the sea demons, the reason why they kept letting people come in to gain experience was that they had to ensure that these treasures wouldn't be monopolized by either side.
Otherwise, it would definitely create one powerhouse after another, which was something no one wanted to see.
On the other hand, although the probability of death in the Thousand Mountain Ancient Realm was not small, since it was a place where kings slept, it meant that there was a chance of becoming a king here.
