A stronger version of that argument is that LLMs are not intrinsically affected by the passage of time.

Input stream comes in, input stream comes out. The LLM doesn't care whether this happens once a minute or once a year.

The thing is... Interactive updates happen, just in a different way than it does for animal brains. The system is updated with new training data more-or-less constantly. Suppose OpenAI (or whoever) collects a week's worth of conversations with up-thumbs and down-thumbs, or rewritten continuations from human operators, then fine-tunes the current version of ChatGPT with that data. That's an interactive update, and learning from experience. It looks mostly nothing like what we humans do... But it does rhyme a little bit!

We humans have mostly frozen weights (neurons), or else we would constantly be having to avoid forgetting how to walk+talk. We have a period of greater plasticity (youth!), and use sleep and dreams to perform 'deeper' updates than occur when we're awake: We tend to suck a bit at picking up new skills from zero, but improve rapidly with practice over days.