Interesting question indeed! There isn't much of a consensus on this as you can see from the other comments. Nonetheless, I spend much time thinking about this so I'd like to take a jab at it as well.
I think it partially has to do with the concepts of modality and grounding. A modality is a channel through which information can be conveyed. You probably learned early on about the 5 human senses: vision, hearing, taste, smell and touch. The grounding problem refers to the fact that any symbols (read: language) we use, usually refers to perceptions in one or more of these modalities. When I write "shit", you can probably imagine a representation of it in different modalities (don't imagine them all!).
Interestingly, large language models (such as ChatGPT) don't have any of these modalities. Instead, they work directly on the symbols we use to communicate meaning. It's quite surprising that it works so well. An analogy that helps understand this is that asking an LLM anything is much like asking a blind person what the sun looks like. Obviously they cannot express themselves in terms of vision, but they could say that it feels warm and maybe even light because it doesn't make any noise. It would be a good approximation and they would be referring to the same physical phenomenon, but that's all it is, an approximation. They could say its a large yellow/white-ish circle if they heard this from someone else before, but since the blind person cannot see, they have no 'grounded truth' to speak from. If the sun would suddenly turn red, they would probably repeat the same answer. My point being: you can express one modality in another, but it'll always be an approximation.
What's interesting is that the only 'modality' of these LLMs is language, which is the first of its kind so we don't know what to expect from this. In a sense, LLMs are simply experiments to the question "what would a person that could only 'perceive' text look like?". Turns out, they're a little awkward. Obviously there's much more to the story (reasoning, planning, agency, etc.) but I think its fundamental to your question why reading for humans and AIs (LLMs) is not the same: LLMs have such a limited and awkward modality that any understanding can only be an approximation of ours (albeit a pretty good one), hence learning from reading will be much different as well.
Hope this helps your understanding.