The ones HN users find useful are inherently clickbait, a user scrolls by and sees an unknown concept "Heffer's Law" [1] because the description doesn't fit neatly in a title.

They belong in a comment where appropriate context is a given.

[1]: made you look

There are still plenty of them being submitted (I can see a dozen in the last day); but most of them don't get many upvotes so don't make it to the front page.

Maybe people are getting bored of them? Or maybe many the most broadly interesting ones have already been posted os they're becoming increasingly niche?

Are you upvoting the ones in new? And are you seeing less engagement when you post them?

Just bookmark the site=wikipedia feed:

https://news.ycombinator.com/from?site=wikipedia.org

In organic search, Google's ranking algorithm takes into account various SEO factors like content quality and backlinks. For high-traffic search queries, thousands of websites compete fiercely for visibility, employing all sorts of optimization tactics. Wikipedia, while a treasure trove of information, doesn't actively engage in such SEO practices, putting it at a disadvantage compared to these highly optimized sites.