"the fundamental problem facing publishers – the fact that Facebook and Google dominate the online ad business and online content discovery channels."
The publishers have only themselves to blame.
In print they've sold advertising space and put it on the pages themselves. Online they chose to hand it over to Google.
For search - and this applies to far too many vendors' sites as well as publishers - on-site search is generally so poor that all too often it's easier to go to an external search engine than try to find what you're looking for on the site itself. This includes at least some of the largest tech vendors who really should know better.