There was definitely a bit of Pournelle's Iron Law of Bureaucracy [0] at work. I worked there during a lot of the drama you allude to, and... It sucked, for everyone. But also...

For most of SO's history, the vast majority of visitors (and this questions, answers) came in via Google. Not "search engines"; Google. This was pretty much baked in right at the start, and it effectively served as the site's primary user interface for years. And it worked. It worked pretty well! Until it didn't.

At some point, Google started surfacing fewer "tried and true" Q&A examples and more unanswered, poorly-answered or moderated examples. This broke the fundamental assumption that sat behind SO's moderation - that curating a smaller set of posts was preferable to encouraging more, and newer. Suddenly, Google wasn't a very good UI for SO anymore.

...and SO didn't really have a fallback. Heck, for a while during this period they actually stopped showing questions on their homepage unless you were already logged in; the core assumption remained that there was a never-ending spring of new people feeding the thing. LLMs weren't the start of the problem, they were the end - the final wake-up call.

I don't know that a site like SO can exist without the old Google, the old Internet; it is a product of all that, in the same way that mass-market TV shows were a product of 20th-century broadcast technology, or trade paperbacks of a particular intersection of printing tech and reading habits.

[0]: https://www.jerrypournelle.com/reports/jerryp/iron.html