What Do You Think the Mawsworn by the Waystone are Thinking?

Technically speaking the Jailer could like

I dunno

Pick up a few buildings and throw them on the waystone, burying it under 30 feet of building rubble.

Then again that logic applies to a ton of fantasy trope gateways, so the Jailer is contractually obligated to be as stupid as any other fantasy trope villains.