Wikipedia is Creative Commons. Someone could conceivably publish a dead tree version that goes through an editor / editorial process.

Imagine being an editor of Britannica. Without having domain knowledge into absolutely everything, you are forced to trust domain experts.

Wikipedia has a marked advantage when it comes to building that trust, as the articles have been written under public scrutiny and with a great deal of discussion.

What else are you looking for with "traditional editorial structures"? Consistency in quality and completeness, which Wikipedia lacks. However, whenever an article has lower standards, Wikipedia is happy to point that out to the reader, and allow further refinement. A more traditional encyclopedia would simply omit the article entirely.

I'm not really seeing what a traditional editorial structure would be gaining anyone, seems like it would just be a smaller encyclopedia.