You can message pass across a cluster. In fact, it's identical code to message a remote vs local process.

Erlang provides "process groups" that allow you to structure groups of processes across a cluster.

It doesn't try to be magic. It's not a workload scheduler or "automatic distributed machine".

You structure things the way you want, on top of it's primitives. It's just that all of the primitives you need are built in and work really well.