It’s worth pointing out that while “philosophy” is a big broad subject with implications for all kinds of knowledge, it’s only the Inevitable Word by virtue of a few very contingencies. One of them is that the main “feeds” into it, other big-topic articles, are going to be pretty ossified in the text of their first paragraph. You’ll be more likely to have your edits for the “idea” page accepted if you’re adding a little nuance three pages down than if you’re trying to reframe the whole concept in the first sentence. So this may be true now, when Wikipedia is a hundred bajillion pages, because it was true when it was merely a few zillion.
Another is Western cultural influence. “Philosophy” is not only broad in its definition today, it’s been a catchall category for lots of abstract concepts in lots of different times, and most of those senses survive in the English word. I don’t know if you get the same result from zh.wikipedia.com (Chinese-language Wikipedia) but if that site had developed in a vacuum (no borrowing from the English-language version) you might very well have gotten a different Great Attractor.
And finally (he said, driving home the point nobody asked for), some of this derives from the basic template for writing these articles. Best Wikipedia practices are to start with as general an overview of relevant concepts as possible, situating your topic in terms of the classes of things it belongs to. That’s going to skew towards the abstract and broadly-defined.
Now, you may ask, why do I care? Because I’m a history professor. If I’m not undermining philosophy, what am I even doing with my life.