I think the example of the NPC follower in Skyrim is a great place for it, being able to ask your follower “which way to Riften?” is kind of neat, giving them commands like “go stand by the rock and attack the wolf when they get close”. For actual dialogue, take Johnny in Cyberpunk or Liara in Mass Effect, there’s no way AI can stand in for voice actors.
I’m thinking shop owners, random NPCs, etc. Little bits of dialogue.