People keep saying it because that's literally how LLMs work. They run Montecarlo sampling over a very impressive latent linguistic space. These models are not fundamentally different than the Markov chains of yore except that these latent representations are incredibly powerful.

We haven't even started to approach the largest problem which is moving beyond what is essentially a greedy token level search of this linguistic space. That is, we can't really pick an output that maximized the likelihood of the entire sequence, rather we're simply maximizing the likelihood of each part of the sequence.

LLMs are not reasoning machines. They are basically semantic compression machines with a build in search feature.