You're totally right.
Endgame/story goals are something that have been on my mind a lot.
I have some superficial plans like achievements to hunt, a bestiary complete, a catalog of items to collect, speedruns or endurance runs . Also some more concrete ideas like adding a progressive boss rush, and boss battles to the end of each zone, as well as more advanced aspects of the town to work towards and use resources on.
Dwarf Fortress is hugely influential to me, I'd love to be able to cultivate something like that level of flavor and endless storytelling.