It's really great for very concrete topics like "What are the exact specs for USB3".
The more you get into social sciences and the arts, it becomes a question of who wants it more.
Meaning if a particular viewpoint has someone who is willing to watch the page every day for changes by "the evil people who believe the opposite from me", then that viewpoint prevails.
And then when 12 year olds look up the topic for homework, that is the viewpoint they get.
The saying should be "History is written by those who are the most obsessed with Wikipedia editing."