We should have some faith in our official institution but were all human. If anything being an expert can make people more prone to serious mistakes because of bias.

Its in everyone interested for the public to speak up fast if official information is wrong or dangerous.

The downvote thing is an old issue though. I actually see many other problems but believe it will still end up a net plus.

My main concern is who choses the expert? Will it be a local one? in the users own language? Or will YouTube hire their own experts to make these videos themselves.

What do they do if doctors cant agree on a best method but multiple methods have videos online?