The issue with the current generation of models is that they can't reason, they may do very well at pretending to reason, but they can't [1]. Reasoning requires the ability to identify and reuse patterns, and while there has been some advancement in this area [2] with getting models to learn the underlying pattern and rule, it doesn't generalize. This results in models that will happily tell you that a statement is both true and false, and be unable to identify the logical problem with that.
Even creating summaries is difficult, and LLM's are more than happy to hallucinate even when summarizing documents, providing incorrect, or entirely made up facts [3]. The general workaround is multiple runs with the same work and averaging the response, but that's a lot of work, and energy.
[0] https://win-vector.com/2024/05/21/i-want-flexible-queries-no...
[1] https://medium.com/@konstantine_45825/gpt-4-cant-reason-2eab...
[2] https://arxiv.org/abs/2405.15071
[3] https://community.openai.com/t/gpt-4o-hallucinating-at-temp-...