The player characters should have voiced dialogue for feedback purposes, like "Let's see if this works" when crafting, because an animation plays and if you don't notice, it looks like they're not doing anything.
Maybe they also should have some of their floating text dialogue voiced, because occasionally, it can be hidden by other messages or the inventory screen (some of the floating text dialogue is triggered by using an inventory item, so it can be obscured if it's just text.)
They don't need voice for conversations with NPC's, even if it wasn't cost-prohibitive.
