AI is already destroying humanity. All the algorithms that drive content distribution are producing society polarized to the extreme. We consume media that some machines decide to serve us with one goal: grow engagement.
AI destroying humanity is not robots crushing skulls, but automated services mushing brains.
AI always answers the same too, if the inputs are the same. The trick is to use a hidden input that keeps changing, like the current time, and you can do the same with any algorithm.
AI is just a really advanced algorithm. (Or sometimes not so advanced, if you include types of AI that aren't LLMs.)
Also, AI is behind almost all algorithmic content delivery. You can just google it and find articles like How AI Influences What You See on Facebook and Instagram. Every closed-source platform is using it, except maybe reddit, but that's only because they have a ton of technical debt that makes it difficult for them to change core systems.
Of course it's true that AI is "just" a tool, but it's a tool that makes it a lot easier to manipulate people, and it's already a huge problem.
AI in its current state is an algorithm. Given a temperature of 0, an AI SHOULD always give the same answer for the same input (but there is currently a bug in chatgpt that makes it not so)