Claude Sonnet 3.7 Thinking is also an unmitigated disaster for coding. I was mistaken that a "thinking" model would be better at logic. It turns out "thinking" is a marketing term, a euphemism for "hallucinating" ... though, not unsurprising when you actually take a look at the model cards for these "reasoning" / "thinking" LLMs; however, I've found these to work nicely for IR (information retrieval).
Overthinking without extra input is always bad.
It's super bad for humans too. You start to spiral down a dark path when your thoughts run away and make up theories and base more theories on those etc.