The Apple study was clear about this. LLMs and their related modal models lack the ability to abstract information from noisy text inputs.
This is really obvious if you play with any of the art generators. For example - the understanding of basic prepositions just isn't there. You can't say "Put this thing behind/over/in front of this other thing" and get the result you want with any consistency.
If you create a composition you like and ask for it in a different colour, you get a different image.
There is no abstracted concept of a "colour" in there. There's just a lot of imagery tagged with each colour name, and if you select a different colour you get a vector in a space pointing to different images.
Text has exactly the same problem, but it's less obvious because what the grammar is usually - not always - perfect and the output has been tuned to sound authoritative.
There is not enough information in text as a medium to handle more than a small subset of problems with any consistency.