Not always, I think that is an unfair reflection of LLM's in their current state. See two trivial examples below:

https://chat.openai.com/share/ca733a4a-7cdb-4515-abd0-0444a4...

https://chat.openai.com/share/dced0cb7-b6c3-4c85-bc16-cdbf22...

Hallucinations are definitely a problem, but they are certainly less than they used to be - They will often say that they aren't sure but can speculate, or "it might be because..." etc.