Think about the ways that LLMs interact. The constant barrage of positive responses "brilliant observation" etc. That's not a healthy input to your mental feedback loop.
We all need responses that are grounded in reality, just like you'd get from other human beings. Think about how we've seen famous people, businesses leaders, politicians etc go off the rails when surrounded by "yes men" constantly enabling and supporting them. That's happening with people with fully mature brains, and that's literally the way LLMs behave.
Now think about what that's going to do to developing brains that have even less ability to discern when they're being led astray, and are much more likely to take things at face value. LLMs are fundamentally dangerous in their current form.