It’s every bit as comprehensive and isn’t a biased mess.
I agree that there are definite bias issues with Wikipedia and this led me to research several alternatives. Unfortunately, some of the best potential competitors are woefully lacking in updates. Many basic articles on places like Infogalatic, Everipedia, and Citzendium haven’t been updated in years (except information about cryptocurrency on Everipedia, which seems to have turned into a specialty wiki on the topic).
I’m afraid that means they just aren’t going to be helpful to many users of Brave Search.