These networks don't need a dozen devs working on the core protocol, they need thousands of devs all contributing in a way that makes sense.

I think that smart contract platforms have this in a way.

The core team handles the blockchain development but, once this reaches a certain level, the main development is in creating the apps. And this is done by a large number of individual teams.

Since smart contract development follows a functional programming / lego block approach, future teams can leverage different elements of work done by prior teams. So there is a level of integration / coordination and building together.