I suspect that the arrival of ChatGPT caused traffic to the MDN Date API documentation to go down by at least half.
Go down by half of user traffic, go up 10x of crawler traffic.
Built a scheduler with pretty much all my moment/moment-tz questions answered through ChatGPT. One of the things it excels at, crawling long lived API documentation, answers, etc.
The Date API is fine and relatively normalized. Once you understand it it's very easy to work with. It's biggest problem is that it simply does not support timezones, which is the main reason to use Temporal.
To be fair it's exactly the type of stuff I'd be glad if I never have to think about again.