If you answered that the South American turquoise swarklebug is a swarklebug with a turquoise shell whose home region is South America, you won!
A Wikipedia article whose lede doesn't begin with that degree of simplicity, obviousness, and hyperlinking is usually ripe for improvement.
How many examples can you find and fix today?
Ontology in general is complex, and we aren't going to "reach the end of it" on Wikipedia; but applied or practical ontology is a big part of the difference between (1) being ignorant, or being only narrowly educated in certain areas, and (2) being broadly and deeply educated. And most applied or practical ontology is oddly simple, once you've figured it out, despite seeming mysterious before that. Often it is only a matter of recognizing, for example, that there are wikilinks that should be in this lede, but aren't yet. And it's not that hard to realize that in the article on (say) iron oxides, the words iron and oxygen, with links to those elements' articles, should be in its lede—indeed, in the opening sentence of that lede. It's not even hard. And yet Wikipedia to date is still full of ontological gaps. Which (if you think about it) reflects on us humans, the default ways we tend to think, and what low-hanging fruit is available in improving upon them, even while acknowledging and accepting their humanity. And most practical ontology could be greatly elucidated at Wikipedia and Wiktionary (the two working together) if enough critical thinkers worked earnestly on those projects. Imagine a world in which 99% of the practical ontology that most people ever need was fed seamlessly to them, instantly, for free, and on demand, by Wikimedia projects. It would mean that when they land on the article about the South American turquoise swarklebug, they are going to understand within seconds (not by doing a bunch of further research) that it is a swarklebug with a turquoise shell whose home region is South America. And within only a few degrees of separation that can be jumped at the speed of a hyperlink, they will be able to tell, if it occurs to them to ask, what other kinds of swarklebug exist, what other things exist that are turquiose, where South America is, what an insect is, what other insects live in South America, why turquoise is called turquoise, and so on. Wikimedia can facilitate that, if people will simply bother to build these projects. We are not there yet—not nearly. You may find portions of Wikipedia that feel like they have arrived at that juncture—for example, the iron oxide articles of the Wikipedian world mostly already say "iron" and "oxygen" in their ledes—but I can guarantee you, from being one of the volunteers working away, out in the weeds, that in some of the areas that matter most to human health and economics, we are not yet even close. So grab a hoe and come help.