Final Thoughts

If the goal is to create emotional immersion in a game, then we need to make the NPCs life-like. Drawing upon NPC Chemistry Techniques helps create that sense of realistic relationships between the NPCs, in cases where they're supposed to be friends, lovers, and so on.

Conversely, setting up a situation where two NPCs are supposedly friends or lovers, and not using such techniques, pulls us out of the game because it will feel unnatural and the poor writing (or lack of Emotioneering) will stand out and call attention to itself.