Yes I had the same thought, then I guessed parent might be referring to how wiki doesn't present topics in a way that's easily digestible for someone approaching new topics in math, which I can get behind. It is an encyclopedia after all.
I came here to post that simple wikipedia exists :) . Just to prove your point, have a look at the simple page for "Prime number" [0] and the regular page for the same [1]
If I were just starting out with mathematics, I'd be rather intimidated by the regular page. I find the simple version to be the right start for any topic and then move on to the regular one.
What do you think are the problems with the regular page?
I just skimmed it, and it seems to me like high-school level math is more than enough to understand what the page is saying (at least superficially).
I get the idea behind simple.wikipedia.org, but more often than not it's just a dumbed down version of the main article that uses worse English (which is obvious, since it presumably has less contributors than en.wiki, but that doesn't help your average reader)
@qsort:
To give you an analogy, think of the "original" wikipedia article as the equivalent of an academic paper. It is absolutely the right level of detail for a particular audience (with references and links and even fancy language) whereas the simple wikipedia article is the equivalent of a NYT article introducing the same idea and probably going a bit deeper.
As a further analogy, if I had to learn about Covid-19, I'd likely start with NYT (no affiliation) and then move onto Nature/Science/BMJ