Here's an example of how Wikipedia's reliable sources rule works in practice.
The New York Post is blacklisted on Wikipedia. You can't use it as a source. Now yes, the Post is a tabloid and it is a bit clickbaity, but it also does journalism. That's why its coverage of Hunter Biden's activities had to be shut down by Big Tech during the 2020 election.
I've been keeping an eye on Hunter Biden's wiki page for several years. It's very interesting. Until quite recently a reader would have got the impression that Hunter is a beloved and universally respected public servant, and mean nasty Republicans have been making up baseless conspiracy theories about him, but those stories are mean and nasty and baseless, and if mysterious foreign businessmen give Hunter large sums of money for no obvious reason, there's nothing shady about that.
If you read the NY Post, they'd flat out tell you that the Biden family are corrupt grifters. But the NY Post is not a reliable source.
Now, since Joe Biden is no longer president, and reliable sources are prepared to allow criticism of him, and even coverage of Hunter's interesting legal challenges, Wikipedia's position has become untenable, so Hunter's page is a convoluted mess that mentions his dodgy activities while putting in lots of disclaimers insisting that there was nothing dodgy about them, and certainly nothing dodgy linked to Joe. For instance, Joe getting that Ukrainian prosecutor fired is still a false conspiracy theory, because Joe denied it and reliable sources backed Joe up, and the totally honest diamond geezer government of Ukraine backed Joe up.
The upshot of all this is that, if you'd spent the past five years reading the NY Post, you'd be significantly better informed about Hunter Biden than if you relied on Wikipedia, and if you read Hunter's wiki page now the conclusion you will draw is "this Hunter Biden guy seems really dodgy, and for some reason Wikipedia is trying to hide that".
Now multiply that across any of the controversial issues Wikipedia covers. It isn't achieving accuracy by crowdsourcing. What it's doing is sustaining a narrative by cliquesourcing.