Another thing that has failed: journalists. They get sent press releases and do the filtering. Something like 80% of 'news' is PR. But they don't want you leaving their news website. That would be bad for revenue, allegedly.
Imagine a 'newsworthy' story about a budgerigar that can dance to jazz music. The source could be on a website that has all kinds of fascinating stuff about budgerigars. But this you would never know, perhaps you might get a link to the original tweet but that would be it, no link to the website that gave rise to the one thing that went 'viral'.