Should it? Such liability inevitably results in only "verified" content getting "promoted" - an extremely vague term. First it's the home screen, then related videos, then 1st page results for searching "cleanse", etc.
Soon any kind of user content hosting becomes legally impossible without acceding to some kind of government-approved (it will be private, but require "good standing") censorship agency.
Soon any kind of user content hosting becomes legally impossible without acceding to some kind of government-approved (it will be private, but require "good standing") censorship agency.