The full decentralized web stack I believe is now there.  Nostr is one component in it, namely the relay component, but there are many other components in it, for example bitcoin for payments, and other solutions for storage, and so on.

The challenge now is to roll it out.  A solution is not enough, people need to be ready for that solution.  You can only successfully roll out a solution that people are ready for.  Even to a small group.  So the skill becomes finding which part of the stack people are ready for.

Interestingly, machines will be part of a future stack for the first time.  The roll out to machines will be different to the roll out to humans.  But potenially more impactful.