It's enjoyable to read the responses when you cannot do something. It's part of the game, baked into it.
More importantly, you and me will get the same shared experience we can discuss, unlike if we were playing with an LLM going on different, random tangents.
> Arguably, different responses would increase replayability.
Yes, but I don't think we're talking about the same kind of replayability. Certainly, not the kind I care about.
To me, replayability is a carefully constructed experience, by an author, and you explore it and find different things about it (say, like Adam Cadre's "9:05" [1]). But you can share your experience with another human, you can both go the same way and experience the same thing, and discuss it -- "hey, remember when you face the trolls in the cave, and...".
With an unconstrained LLM, you lose this. Plus, with no authorial voice behind it, I don't really care what a glorified stochastic automaton can produce.
(In case you're wondering, I find myself distancing from classic sandbox games as well... I used to like them, now I find them "too much work" for not enough payoff. With some exceptions, I much prefer a carefully curated gameplay experience).
If not, perhaps it's already using a LLM?