Wardstones were considered archaic and out of date back on Earth, as the number of different protections that could be anchored was very limited. If an enemy got to the wardstone, they could disable all of your protections quite easily. Though, to be fair, this room was nearly impossible to enter being seventy metres under the ground and behind an unbreakable wall. Once inscribed, you could not replace any of the runic matrixes on the wardstone and the only way to change your protection was to simply replace it with a new, unused one.