What's frustrating for me is that there is clearly a place for a new vision for the web beyond what the "Web 2.0" vision provided: client-first rich web applications that offered desktop-like capabilities. Along with that are the social/centralization/managed "pros/cons" that a lot of commenters decry. But this was the economic model, not the technical one.

"Web 3.0" should be indeed be about decentralization-- but more in the sense of building applications that take advantage of the enhanced client abilities and de-emphasize central control. The colloqiual term is the "Fediverse". The modern web has brought about offline support (ServiceWorker), multi-processing (Web Workers), local capabilities (Filesystem API, local/DB storage, peripheral APIs) interprocess communication (Broadcast Channels), peer to peer (via disinterested party HTTP/WebSockets coordination), verifiable privacy via encryption, backend server federation (see Mastodon, Matrix, diaspora, PeerTube, etc).

Web 3.0 already exists, we just hadn't named it yet, but there's so much more there to be built.