These are not similar. Wikipedia says the same thing to everybody, and when what it says is wrong, anybody can correct it, and they do. Consequently it's always been fairly reliable.
In fact, the error might even be a good thing; it reminds attentive readers that Wikipedia is an unreliable source and you always have to check if citations actually say the thing which is being said in the sentence they're attached to.
Comments like these honestly make me much more concerned than LLM hallucinations. There have been numerous times when I've tracked down the source for a claim, only to find that the source was saying something different, or that the source was completely unreliable (sometimes on the crackpot level).
Currently, there's a much greater understanding that LLM's are unreliable. Whereas I often see people treat Wikipedia, posts on AskHistorians, YouTube videos, studies from advocacy groups, and other questionable sources as if they can be relied on.
The big problem is that people in general are terrible at exercising critical thinking when they're presented with information. It's probably less of an issue with LLMs at the moment, since they're new technology and a certain amount of skepticism gets applied to their output. But the issue is that once people have gotten more used to them, they'll turn off they're critical thinking in the same manner that they turn it off when absorbing information from other sources that they're used to.
For politically loaded topics, though, Wikipedia has become increasingly biased towards one side over the past 10-15 years.
You can check them, but Wikipedia doesn't care what they say. When I checked a citation on the French Toast page, and noted that the source said the opposite of what Wikipedia did by annotating that citation with [failed verification], an editor showed up to remove that annotation and scold me that the only thing that mattered was whether the source existed, not what it might or might not say.
The weird part is when people get really concerned that someone might treat the former as a reliable source, but then turn around and argue that people should treat the latter as a reliable source.
[0]: https://en.wikipedia.org/wiki/Equivocation
[1]: https://chatgpt.com/share/67e6adf3-3598-8003-8ccd-68564b7194...
See the Wikipedia page on the subject :)
If you read a non-fiction book on any topic, you can probably assume that half of the information in it is just extrapolated from the authors experience.
Even scientific articles are full of inaccurate statements, the only thing you can somewhat trust are the narrow questions answered by the data, which is usually a small effect that may or may not be reproducible...
Newspaper articles? It really depends. I wouldn't take paraphrased quotes or "sources say" as fact.
But as you move to generally more reliable sources, you also have to be aware that they can mislead in different ways, such as constructing the information in a particular way to push a particular narrative, or leaving out inconvenient facts.
Nonfiction books and scientific papers generally only have one person, or at best a dozen or so (with rare exceptions like CERN papers), giving attention to their correctness. Email messages and YouTube videos generally only have one. This limits the expertise that can be brought to bear on them. Books can be corrected in later printings, an advantage not enjoyed by the other three. Email messages and YouTube videos are usually displayed together with replies, but usually comments pointing out errors in YouTube videos get drowned in worthless me-too noise.
But popular Wikipedia articles are routinely corrected by hundreds or thousands of people, all of whom must come to a rough consensus on what is true before the paragraph stabilizes.
Consequently, although you can easily find errors in Wikipedia, they are much less common in these other media.
Wikipedia being world-editable and thus unreliable has been beaten into everyone's minds for decades.
LLMs just popped into existence a few years ago, backed by much hype and marketing about "intelligence". No, normal people you find on the street do not in fact understand that they are unreliable. Watch some less computer literate people interact with ChatGPT - it's terrifying. They trust every word!
One of these things is not like the others! Almost always, when I see somebody claiming Wikipedia is wrong about something, it's because they're some kind of crackpot. I find errors in Wikipedia several times a year; probably the majority of my contribution history to Wikipedia https://en.wikipedia.org/wiki/Special:Contributions/Kragen consists of me correcting errors in it. Occasionally my correction is incorrect, so someone corrects my correction. This happens several times a decade.
By contrast, I find many YouTube videos and studies from advocacy groups to be full of errors, and there is no mechanism for even the authors themselves to correct them, much less for someone else to do so. (I don't know enough about posts on AskHistorians to comment intelligently, but I assume that if there's a major factual error, the top-voted comments will tell you so—unlike YouTube or advocacy-group studies—but minor errors will generally remain uncorrected; and that generally only a single person's expertise is applied to getting the post right.)
But none of these are in the same league as LLM output, which in my experience usually contains more falsehoods than facts.