Exactly this - I've said it before and will say it again - new technologies emerge in response to trends, often to accelerate existing trends and does not create them.

I see a few explanations for what you're saying, and those might be true, but I strongly believe part of it is investment (particularly VC, less so PE) has hit diminishing returns in tech and which means less subsidized "disruption", which means less money to hire people. AI becoming hugely popular right when this was happening is not a coincidence. And it's not just startups, less investment in startups also mean less clients for AWS and Azure. A16Z / Sand Hill switching to AI is not them just chasing the latest trend, it's a bid to reduce cost on people, which is the most expensive part of a tech company, as the only way to extend their unicorn-focused investment strategy.