People may be dismissive of Serverfault and the other sites but pretty much all LLMs are trained on them.
Yes, it's like a lot of other content that no one will bother to maintain anymore because it is easier to ask an LLM. Not sure where they are planning to get their new training data from ...
And all the sites trained on humans, something which we never found offense with, for some interesting reason.
It was great while it was good. The demise wasn’t quality as such, but rather the insane moderation - closing everything as duplicates or out of scope etc.