> It's about the same as talking to yourself

In one way it's potentially worse than talking to yourself. Some part of you might recognize that you need to talk to someone other than yourself; an LLM might make you feel like you've done that, while reinforcing whatever you think rather than breaking you out of patterns.

Also, LLMs can have more resources and do some "creative" enabling of a person stuck in a loop, so if you are thinking dangerous things but lack the wherewithal to put them into action, an LLM could make you more dangerous (to yourself or to others).