One can't answer the question as to how accurate
Wikipedia is with a simple
yes or
no. What has emerged, I think, is that some printed encyclopedias aren't much more accurate - which could point to a more general problem with non-specialized encyclopedias. I know two people (former colleagues) who have contributed to conventional reference works. One was interesting and well aware of new ideas, the other could be relied on to repeat the conventional line on most areas of his subject.
With
Wikipedia I now make a point of looking at the discusssion page of anything likely to be controversial. Some people use
Wikipedia rather like Speakers' Corner in Hyde Park. Out come the soap-boxes, and there are the ignorant gleefully rubbing shoulders with experts.
I've encountered some horrendous examples of ignorance and/or 'soap-box oratory' in
Wikipedia and have drawn attention to them in this thread. The most recent is the article on a supposed medieval
Kingdom of Germany. If you do a Google search for "Kingdom Germany" the only direct hit is that article. The other hits (if that's the right word) are for things like '... United Kingdom, Germany'

Having said all that, I still find
Wikipedia useful for many purposes and often use it, with a pinch of salt.