The role of curation has been eliminated as the majority of value is captured by the platforms so it is  no longer economically viable. With fewer and weaker intermediaries, we also reduce the amount of independent points  of views or windows to the world.

As Web 2.0 companies began to deeply understand the powerful potential of their innovations — the game-ish reaction buttons, the follower graph, the algorithmic ‘newsfeed’ — they became adept at a clever stratagem. Rather than committing to perpetual openness, they could offer new user tools or developer APIs and encourage the community to use them... See more

curation platforms are also able to achieve unique relationships with their end consumers. They win trust by limiting supply and creating opportunities for consumers who were traditionally more passive users of the internet to participate more actively by lowering the barrier to entry for “curation as creation.”