downsides of using Wikipedia as a source?

Over time, I've found Wikipedia to be quite biased in a subtle way. Articles about cities or countries tend to be written like advertorials, replete with rankings rather than facts. Articles about religious figures, philosophers or just controversial people in general tend to be more obviously biased, with certain facts highlighted and others buried or hidden.

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:

https://www.britannica.com/place/Vienna

https://en.wikipedia.org/wiki/Vienna

Wikipedia articles are a very mixed lot: sometimes the articles are great; most of the time they are adequate and part of the time they are inadequate or incorrect.

A big question is how important the answer is to you: if it is of major importance you need to do more comprehensive research.

Wikipedia prose is very disorganized, strange, and hard to read. Pages are like school assignments cowritten by dozens of authors. There is no professional editing. This can make you feel stupid—how come I read and read but somehow fail to understand or remember? So trying to use Wikipedia for getting an overview of a complex topic is a bit of a waste of time compared to a “real” encyclopedia article.

It can be biased. Not every article is, but some certainly are. If you speak other languages besides English, pick a couple of historical events, political groups, and in general contentious topics and compare their article in English and other languages. You will be surprised how different they portray the same event and how the choice of facts to present and how to present them totally changes the narrative.

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.

I think the only issue I have come across, very occasionally, is that information in an article is changed or updated or removed. It's possible to see the edit history, but it's not optimal. You could save an offline copy for certain articles but then they won't get updated. Edits due to political reasons in a technical article are annoying.

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.

Wikipedia is not an original source for research. It just references other sources in their text, which is why researchers cringe if the majority of your sources is based on Wikipedia unless for good reason.

Wikipedia can be a worthwhile place to look for very general descriptions to give yourself an introduction to new ideas. much like you're already using 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.

A lot, if not most, of the full-time editors are paid shills.

So the information is bought and paid for.