I'm actually extremely confident that I can use the architecture to make a sweeping claim on what it can or can't do and will be extremely surprised if proven wrong:

A pure next-token language model won't be able to give detailed instructions to an ensemble of motors, mimicking a human body, to do a wide variety of tasks our human brain is excellent at doing, for example, inserting keys into a car, opening the door, sitting down, starting the car, putting the car in reverse, and exit a parking lot, being careful not to hit anything.