[lapetitejort]

You, the real human, cannot say whatever you want to the NPCs. Instead you either have to rely on a few scripted choices, or a silent character. Neither of those are very fun. Interactive also implies the ability to change outcomes. That is also difficult as every outcome requires writing, animating, etc. So games give the illusion of choice with a few well defined branches, then railroad you into a few endings.

Another approach is to not craft an explicit narrative. Just give a fleshed out, lived-in world and let the person explore. Let knickknacks, street trash, architecture, NPC behavior, etc tell the story. How can a game describe a dystopian world without an NPC saying "I sure do hate being oppressed!" and giving a questline for toppling the government? Maybe draconian transportation systems, NPCs eyeing the character if not dressed right, ugly architecture seeping into established spaces.

[jerf]

Yeah. Basically, imagine a world in which every single player of Final Fantasy X had a full DM behind them. Even if we stipulate the entire world prepped as a playground beforehand, who knows what you'd get up to in such a scenario? Who knows how radically divergent all our experiences would have been?

Such a thing is simply impossible today, and for the forseeable future. The closest you can get is AI dungeon, and IMHO and with all due respect to the creators, that's little more than a glimpse at the possible future, it is as far away from this reality as Pong is from FFX.