That's all they can do. They seem impressive at first because they're basically trained as an adversarial attack on the ways we express our own intelligence. But they fall apart quickly because they don't have actually have any of the internal state that allows our words to mean anything. They're a mask with nothing behind it.
Ctrl+F for "Central nervous system":
https://en.wikipedia.org/wiki/List_of_human_cell_types
Choose any five wikilinks. Skim their distinct functions and pathologies:
https://en.wikipedia.org/wiki/List_of_regions_in_the_human_b...
https://en.wikipedia.org/wiki/Large-scale_brain_network
Evolution's many things, but maybe most of all lazy. Human intelligence has dozens of distinct neuron types and at least hundreds of differentiated regions/neural subnetworks because we need all those parts in order to be both sentient and sapient. If you lesion parts of the human brain, you lose the associated functions, and eventually end up with what we'd call mental/neurological illnesses. Delusions, obsessions, solipsism, amorality, shakes, self-contradiction, aggression, manipulation, etc.
LLMs don't have any of those parts at all. They only have pattern-matching. They can only lie, because they don't have the sensory, object permanence, and memory faculties to conceive of an immutable external "truth"/reality. They can only be hypocritical, because they don't have the internal identity and introspective abilities to be able to have consistent values. They cannot apologize in substance, because they have neither the theory of mind and self-awareness to understand what they did wrong, the social motivation to care, nor the neuroplasticity to change and be better. They can only ever be manipulative, because they don't have emotions to express honestly. And I think it speaks to a not-atypical Silicon Valley arrogance to pretend that they can replicate "intelligence", without apparently ever considering a high-school-level philosophy or psychology course to understand what actually lets human intelligence tick.
At most they're mechanical psychopaths [1]. They might have some uses, but never outweighing the dangers for anything serious. Some of the individuals who think this technology is anything remotely close to "intelligent" have probably genuinely fallen for it. The rest, I suppose, see nothing wrong because they've created a tool in their own image…
[1]: I use this term loosely. "Psychopathy" is not a diagnosis in the DSM-V, but psychopathic traits are associated with multiple disorders that share similar characteristics.