Decision making can be done by trained machines following rules, but that's different that reasoning. A thermostat isn't reasoning when it decides to turn on the air conditioner, to argue otherwise expands the definition of "reason" to be so broad that it becomes useless.

LLMs are trained on human knowledge and reasoning that results from human cognition, and they are excellent at stochastic mimicry - if the argument is that they are actually reasoning, then some sort of equivalent to human cognition must be present for that to be true. Lacking that, they are nothing more than "token extrusion machines" with some potentially useful characteristics.