if you actually do use AI to do some proper research on a fields you don't really know that well, looking for peer reviewed papers, actually figuring more things out thanks to AI, then I don't think brain damage will happen.
about your blog post: You jump from a quote about llms hallucinating articles references in students papers, to the statement "if AI does the thinking for you". since when is inventing falsehoods thinking?
The brain damage comes from trusting something other than your own brain to tell you what you understand, believe or know. You wind up thinking you hold positions you can't articulate, have skills you can't actually demonstrate, understand things you can't explain, and it's all downhill from there.
If you're using AI to learn a new field (by which I assume you mean asking it what literature to read, asking questions when you don't understand something, etc.), you are accepting short-term speed in exchange for the long-term growth of research skills. Maybe that trade-off is worth it, if you don't need to master a topic long-term.
If you do need to master a topic, the slow and painful bits are the useful bits. Spending two hours hunting for an answer to something you don't understand increases your familiarity with the available resources, broadens your knowledge base, leads you to thinking of more questions about the subject and to understand your original question more deeply.
Shortcutting all of that with a quick answer from an LLM is not helpful long-term.