https://en.wikipedia.org/wiki/Woman (4th paragraph)
Even if you don't believe that trans women are women, it seems inarguably correct that they identify as women in spite of having been identified as male when they were born. You could complain about the vocabulary, I guess, but there's no set of vocabulary that won't upset someone.
It was a group of editors who conspired to game Wikipedia's rules (for example, "thou shalt not revert more than three times per day" can be circumvented by calling in a friend to revert for you). What makes the story really crazy is that they were exposed by Wikileaks, which published a giant stack of email threads between the conspirators.
This is a run-down of some of the things the most powerful member of the group, an administrator, said: https://wikileaks.org/wiki/Wikipediametric_mailinglist/Piotr....
I find many of the mathematics articles to be difficult to read. I'll look at a mathematics concept that I think I understand (or even use often), and it will be written in jargon that is completely incomprehensible to me.
However, where Wikipedia really has a problem is in contemporary politics. Anything that is even remotely political is probably controlled by one or another clique of editors. There are opposing cliques that battle over every Israel-Palestine article, or over whether to use the Serbian or Croatian name for village X that existed 200 years ago, or about whether hummus is Lebanese or Syrian or Israeli or Levantine. There are also subjects in which one clique has gained complete dominance and is able to completely control a whole topic area. If you start looking at the edit histories and talk pages of articles on one topic, you'll come to realize how influential relatively small numbers of motivated (and sometimes coordinated, though this is against Wikipedia's rules) editors can be.
That's why I'd take anything that's even remotely politically contentious on Wikipedia with an enormous grain of salt.