[derefr]

> "Make a synchronous RPC call between components" is still the "easy" and "obvious" way to get things done.

It all depends on relative friction. Systems designed from the ground up to "think service-oriented" will use languages/runtimes/frameworks that make low-coupling options easier and more idiomatic than synchronous RPC calls.

For example, if your SOA is built on CQRS/ES, then adding an Event to the event store, for another Command to react to, should be easier than making an RPC call.