I love Wikipedia and think it's one of the greatest resources on the Internet, but there's absolutely a lot of bias in Wikipedia. Even within the same language, I think a lot of it has to do with how many people have or are contributing to a page, whether there's a recent event affecting it, how polarizing or political the subject, etc. But it's not hard to find examples of straight up opinions or very incomplete narratives.

I've also noticed huge differences between two different language versions of the same articles. (English/Spanish specifically). Sometimes they even feel independently written.

Of course, we should all do our part to improve these things when we spot them, if we're able.