During my university studies, a few classmates decided to edit a Wikipedia page for a niche technique in our field - changing the article to state it was invented by a rather boisterous member of our group.

The year following our graduation, my classmate heard from the tutor who runs the related course -- asking why the hell his students were claiming he invented such-and-such technique! Several students had cited Wikipedia without checking sources.

To answer your question, Wikipedia is a lower quality source than scientific journals for the same reason direct democracy isn't usually as good as representative democracy. We delegate trust in matters to an authority. Sometimes there are problems with the quality of the authority but at least there is a framework to work within.

It prevents circular referencing. For example, Wikipedia might be referencing Legitimate Science Page, which references Science R Us, which references Science Experts Coalition, which references Wikipedia.

It's because Wikipedia is edited by anonymous people. sources is not to say "this is true because this is written in this source" but "this is true because someone with authority said so". Citing sources is is a form of argument from authority. It is a a fallacy if the source has no authority but a completely valid argument if the source does. Wikipedia has no authority because of its anonymous nature. There's no one to hold responsible and no one who'll lose credibility by publishing bullshit on Wikipedia.

Also, most Wikipedia articles worth citing contain really bad factual errors. Since most readers aren't topic experts they don't notice such errors. But they are there and they are really bad. I only have some math education but I've found lots of mistakes in proofs on Wikipedia. Imagine how bad it is for higher-level math that is beyond the reach of most visitors to the site.

Either the Wikipedia article has a citation for the reference you should use instead, or it needs one and you shouldn't be referencing it.

You shouldn’t cite encyclopedias to begin with. I remember learning this in 6th grade, do they not still teach this? Research 101.

> and have it peer reviewed and approved

That’s the part that matters.

It could be argued that wikipedia has better reviews cause it has a much wider audience of reviewers

Maybe, but my experience editing there is that the very vast majority of edits do not get reviewed at all, let alone by people with any background in the subject at hand.

On overall I agree that having a larger audience is better for WP.

But most WP users are quite passive, and unfortunately a very few are extraordinarily active, so the quality of the WP they patrol, depends heavily of their biases. As they are few, there is no natural moderation.

But having a quality article is not enough, it is also important to have quality articles on a reasonable range of topics, and this is not true for some WP (French WP for example)

Same article since 2012 about cancer vaccines, only 42 words! https://fr.wikipedia.org/wiki/Vaccin_contre_le_cancer

This is interesting, couldn't they just get away with translating the english articles?