It's an example of something where there are a large number of articles missing. I could have given 2 more recondite examples from my areas of interest '-) In some of these areas, redlinks are there. In others, you see a list in unmarked text. I've also had the experience of writing an article and then when I click "What links here" I find there had been half a dozen redlinks that I hadn't known about.
My point is that the common argument that the encyclopedia is almost complete is codswallop based on a very blinkered and parochial view that doesn't even extend to looking at the actual encyclopedia to see redlinks. And I admit I don't even haunt the pages on members of governments, on the geography of Africa or Asia, on the hard sciences or on schools of philosophy.
There are also very real issues with the notability requirement and the deprecation of fringe beliefs bashing into the stated aim of reducing entrenched bias. I think the notability standards need revisiting, and I know that one thing that happens to the type of new editor who wants to create articles is that very often their topic is sneered at. But the idea that en.wikipedia already has articles on most of what is notable - an idea that I am seeing here is also being invoked on some other wikipedias - is just as much a canard as the one that new article creators always choose to write on worthless topics. Not interesting to you personally =/= not worthy of an encyclopedia article, and an encyclopedia should have articles on things that a reader knows little about or hasn't even heard of. That's what it's for, looking things up! It is not for testifying that something has been written about in a lot of other places.