Larry Sanger, one of the founders of Wikipedia, has been banging on about this for years, and in particular how the "reliable sources" requirement was snuck in the back door.
That means, for UK stories, the BBC and the Guardian. The Times might be used with caution, the Telegraph with even more caution, and the Mail is totally blacklisted and may not be used at all.
Oh, and Pink News is a reliable source!
That means, if there's a scandal in the UK and the BBC and Guardian are not covering it, as far as Wikipedia is concerned it never happened. Which is important because of how often lazy journalists rely on Wikipedia.
Personally, I'll still use Wikipedia for questions like "what is the population of Mogadishu", but it's worse than useless for any issue of even slight political or cultural controversy. I stopped being an editor years ago, but once you've seen the back end, the bullying cliques of activist editors with bias on full display, you don't ever forget it.