I know Purge in it’s current state is a mess (to say it mildly), but when I think about it as a game play element, I would prefer ALL Arch priests be captured only this way.
This would encourage players to build bases accessible for the Purge and give them a feasible reward for defeating it. And if Purge wave settings could be adjusted in a way NPC waves would always start demolishing from the farthest point slowly converging on the base itself, it could to some extent offset pillar and foundation spamming issue.