The major change is simply economic: that the product stopped being the publication and started being the article. The public turning point for this granularization was when Gawker decided to play per click in March 2008. As this motivation was generally adopted industry wide, it separated a writers incentives from that of a the publication as a product.
We no longer had a quality bar set by brands, and instead a race to the bottom set by individual writers competition. You can see it everything from click-bait headlines to inflamatory articles, all the way to its final form: Fake news written only for views at the price of all other qualities.