I think, they are trying to push back against generated pages. I faced this exact problem myself. We recently published an interactive source code navigation tool [0] where you can find examples for commonly used functions from some embedded SDKs. Google indexed it immediately and almost immediately it got a spike of views.

Then, an interesting thing happened. Most pages simply disappeared from the results. Search console shows them as indexed, no problems, no manual actions, but if you google up those functions, there results are not there.

It took some statistical analysis to figure out that they appear to be capping the number of pages. Out of all the pages Google crawled, it picked some percentage of the "most important" ones and it's showing those. The importance, by the looks of it, was computed from the number of incoming links, prioritizing pages for common stuff like int32_t that nobody googles.

It's not ideal, but it kinda makes sense. It's 2024. You can use AI to generate plausible content for any search query you can think of. And unless they put some kind of limits, we'll get overrun with completely useless LLM-churned stuff.

[0] https://sourcevu.sysprogs.com/