I feel like you have that exactly backwards? To me it was a shift in roles in the old field of dreams storyline. I.e. "if you build it, they will come".

In Web 1.0, you posted content and an audience came. In Web 2.0, you tried to open an empty field and commenters came and played with each other.

If anything, what happened next was a sort of halfway reversion, as the platforms tried to stratify and monetize two types of user. A subset who were the Web 2.0 contributors and another tier of more passive consumers. I think a lot of the "likes" stuff was also less about self-moderating channels and more about making passive users feel like they're engaging without actually having to contribute anything substantive.