For me, the complexity is missing as far as interaction is concerned, and IMO that is down to one thing - spoken dialogue. It limits the AI's responses to whatever has been recorded. If it ain't recorded - you can't talk about it. I might suggest that AI interaction be about generated conversation not recorded conversation. This means losing the spoken dialogue for the most part.
I say for the most part because IMO wandering around the settlements can still be populated with talking entities, overheard conversations etc. Nothing wrong with that and removing the AI interaction dialogue means that a WHOLE LOT MORE casual conversation can be used. So you wouldn't hear about so many guards with dodgy knees for example all the time.
Upon entering a dialogue with an AI, instead of getting both spoken and subtitled dialogue, I should like to see subtitled dialogue ONLY. That way an almost infinite amount of dialogue can be generated about just about anything the player should like to discuss. Need directions? Ask an AI and it can respond with basic or specific directions (north-east for [distance], or follow X road for example). Ask about a person and the AI might know where they are or what they're doing, and generate a response.
You could even have a system where your current highlighted quest allows you to speak about items, people & locations specific to that quest, giving you control over context rather than bog you down with dialogue options on every topic you know about. And your AI conversation can generate a reply based on it's knowledge of that topic.
This would mean that the game becomes more complex in that you need to actually interact with people to find stuff out for your quest, instead of getting magic arrows to follow or map markers to aim for, you'd need to track down your goal by interaction. The closer you get to your goal, the more specific (and prolific) the generated information. You would need to find locations by looking for them, and by asking about them. How can this possibly be a step backward? In a game about exploration and discovery, I'm often dismayed at the current method of spawning a map location and compass exactly where I'm supposed to go. That's not gameplay for me, that's following a built-in walkthrough.
This would mean that spoken dialogue needs to go though, and I doubt Bethesda would do that, it simplifies things a lot for them I'm sure.
*edit*
Consider also, that as far as your own character is concerned, you already use a text-only system. So you already know how to imagine a voice when you use that.