I don't know how you can say they lack understanding of the world when in pretty much any standardised test designed to measure human intelligence they perform better than the average human. They only thing that don't understand is touch because they're not trained on that, but they can already understand audio and video.
You said it, those tests are designed to measure human intelligence, because we know that there is a correspondence between test results and other, more general tasks - in humans. We do not know that such a correspondence exists with language models. I would actually argue that they demonstrably do not, since even an LLM that passes every IQ test you put in front of it can still trip up on trivial exceptions that wouldn't fool a child.
No you don’t understand, if i put a billion billion trillion monkeys on typewriters, they’re actually now one super intelligent monkey because they’re useful now!
We just need more monkeys and it will be the same as a human brain.
If these systems showed understanding we would notice.
No one is denying that this form of intelligence is useful.