Last year I had to fight tooth and nail to delete some bullshit article based on Cold War era propaganda that nobody bothered to directly scrutinise and criticise (there was thankfully enough related information out there that undermined the article indirectly). These days I checked a dozen books to confirm a term regularly used on WP is made up by whoever created the page two decades ago, so I'll have to try and dispute it. A friend of mine has spent years looking for historical documents confirming some statement that's been repeated by historians in passing since mid-20th century with no proper corrobating info, obviously repeated on WP as well. Sometime last year there was a reddit thread by a relative of some minor desceased celebrity from 90s who said the celebrity's WP article is entirely based on one journalist's sensationalist book that even got their year of birth wrong; the relative was advised to contact WP's legal team to see if they can solve that somehow.
No, these are not major bits of misinformation, but in specific areas and for specific people they are important. Not claiming GWB is still the president of the US is a very low bar that Wikipedia has already passed like 15 years ago, rather I'm talking about the limits of their sourcing policy. Many sources will say who's the current president of a country, but what do you do when there's one source that got something wrong, two other ones that just repeated what the first said (a very common thing, obviously), and nothing else?