We had Markov Chains already. Fancy Markov Chains don't seem like a trillion dollar business or actual intelligence.
Completely agree. But if Markov chains are AI (and they always were categorized as such), then fancy Markov chains are still AI.
An LLM is no more a fancy Markov Chain than you are. The math is well documented, go have a read.
About everything can be modelled with large enough Markov Chain, but I'd say stateless autoregressive models like LLMs are a lot easier analyzed as Markov Chains than recurrent systems with very complex internal states like humans.
Markov chains in meatspace running on 20W of power do quite a good job of actual intelligence