LLMs seem to be inherently dumb: https://machinelearning.apple.com/research/illusion-of-thinking
And from what I can find in recent studies, no, they didn't suddenly get smart. They just plagiarize slightly better: https://www.sciencedirect.com/science/article/pii/S2949719123000213#b7
We found that the models that consistently output the highest-quality text are also the ones that have the highest memorization rate.