On the universal scale on which Wikipedia operates I don't see any, however in particular knowledge domains others seem much better.

Eg Stanford encyclopedia of philosophy.

This is presumably because Wikipedia's brilliant democratic approach has its inevitable downsides which professionally curated resources don't have to deal with.

As far as a universalist resource goes, Quora showed promise in it's early days, and StackExchange still has a powerful presence but I'm not aware of anything that directly competes at the same level of similar knowledge value.