Hmmm. Nah. See. It's a problem with consistency.

The game makes a point of emphasizing that Aradin and his crew were in the area to try to find the Nightsong by reaching the Underdark in that area. The only way down is the temple.

In the temple and the Selune Outpost, the game emphasizes that the clerics had to seal the temple to prevent the Drow from reaching the surface because, it was the only way up.

Halsin says that Ketheric couldn't use his tower at Grymforge because the way was sealed up by the Selunites. So the only other way was via the cursed lands.

The game emphasizes that you can't leave the area by boat, because they were all destroyed. You can't go east because the pass was collapsed. You can't take the road because the bridge was destroyed by the dragon. The only ways that you can literally go are Underdark or Mountain Pass.

But this is contradicted by the Tieflings leaving for Baldur's regardless as if they magically have another way to get there that we don't. Same with the Flaming Fist. If there's another way, why aren't we presented with it? They go out of their way to tell us we can't go those ways for obvious reasons only to let NPCs go those ways.

And the same for the Underdark. They make it a point to say the only way to go is across the lake, but everyone else has seemingly lots of ways In and out. Mysterious ways.

And decrepit literally means elderly and infirm or worn out or ruined because of age or neglect.

So how is it both decrepit and recently inhabited by gnomes at the same time?