This is pretty much just the nature of any publication - there is no such thing as an "unbiased" source of information. Having said that, I prefer the older, more academic ones like Britannica. They tend to be less caught up in the zeitgeist and more descriptive, if a little boring.
Compare these two articles to see what I'm referring to:
“ Vienna is among the least spoiled of the great old western European capitals. Its central core, the Innere Stadt, is easily manageable by foot and public transportation. In a city renowned for its architecture, many of Vienna’s urban prospects remain basically those devised over several centuries by imperial gardeners and architects.”
I think Wikipedia is almost always more boring because of its voiceless, detached, noncommittal style.
A big question is how important the answer is to you: if it is of major importance you need to do more comprehensive research.
You may say the same is true of any source. But unlike most sources, where the writer or publisher of the piece is known and their biases researchable, you won't know who wrote a particular article and what their allegiances are. Besides, most people use Wikipedia as their one and only source of information, so they do not get exposed to different viewpoints and interpretations. It is considered fine with Wikipedia, as it is an encyclopedia and is supposed to be objective. With individual sources, you know you need to read a couple before forming an opinion. With Wikipedia, you may not do the same.
The other issue I have come across is that sometimes the articles from a specific category aren't linked well or aren't equally in depth. Some might be thoroughly researched but another might have a single paragraph.
I haven't come across issues with the information itself, for information unrelated to celebrities and politics.
I feel like this is something that I was taught in 6th or 7th grade that all literate adults should learn.
This same argument holds true for most “news” sources too. I would not call many of the well known “News” sources legitimate “sources”. Just because Fox/CNN/Wikipedia says something doesn’t mean it’s true. Check the citation! If there is no citation/can’t be verified, then the trustworthiness is close to 0 regardless of the person/agency/organization stating it.
However, in areas where I have actual expertise, I've noticed that it gets the technical details wrong consistently. Often 50% of the time or more on complex subjects. My guess from looking at quite a few articles is that much of the text is from repurposed mediocre to bad essays by college students, or at least written at about the same level.
So the information is bought and paid for.