I would argue the decline of techno-optimism started long before LLMs became widespread. If you think back to the late 2010s, the first bricks were starting to fall already (Cambridge analytica, Google’s 2018 … thing). Crypto, NFTs, Web3, etc were held with general negative regard in the beginning of the 2020s, and the tech CEOs like Musk/Zuckerberg/Bezos had all accumulated negative image by then.