If it was in the Outer Boundary, most people would have been ecstatic when given a chance to enter a secret realm. After all, there were fortuitous encounters in secret realms.
Many supreme powerhouses and cultivators who did not belong to any sects or clans often left precious treasures and legacies in secret realms, which they prepared before their deaths. These secret realms were left to fated people to discover them. In the history of the Myriad Worlds, there were many supreme powerhouses who rose to the top through these encounters.
However, there were also malicious powerhouses who left deadly secret realms for hapless people who stumbled upon them just to mess with future generations.
Most people, even the most bloodthirsty, would have the intention to harm the future generation. No matter how vicious they were, they still hoped someone would inherit their legacies. It was also a way to gain peace before their deaths.