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.
[0] https://simple.wikipedia.org/wiki/Prime_number [1] https://en.wikipedia.org/wiki/Prime_number
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)
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
Do you have any suggestions of better sites to read?
The beauty is that nothing prevents YOU from adding clarity to these "needlessly contrived" concepts... so what's stopping folks like you from contributing?
I think post-docs are probably better suited for accurate explanations but at the same time they are (at least, fairly often) not as good at explaining a concept using a simpler framework.
The other problem is that because different editors write maths articles, related concepts can use fairly different terminology or concepts with similar derivations use different derivations leading to possible confusion about how concepts are related.
That’s pretty minor, but it is the main point about Wikipedia that I wish were better (I know, I’m free to help out...).