I believe that the core tenets of the fediverse are the same of Web3. I posit:

Decentralization:

A core aspect of Web3.0 is the push towards a decentralized internet, where users control their own data and interactions rather than these being centralized in a few major platforms. The fediverse embodies this. Platforms in the fediverse operate independently but can communicate with one another, allowing users to switch between platforms.

User Control and Ownership:

In Web3.0, the aim is for users to have complete control over their own data. While the fediverse does not use blockchain technology to implement this, its federated nature does mean that users have a significant amount of control over their data. Users can choose which instance of a service to join based on their values, the rules of that instance, and how that instance handles data.

Interoperability:

Web3.0 envisions a highly interoperable web where data and services can easily be shared and used across different platforms. The fediverse is built on this principle. Different services, whether microblogging sites like Mastodon or video sharing sites like PeerTube, can all interact because they use the same protocol (ActivityPub).