In my experience this just results in the service with a 'single syntax error' dumping stack traces while the services that talk to it throw exceptions as their HTTP requests get 500 responses. Noisy.
RPC is much better suited for a microservice architecture. Leave HTTP for the leaves. (I wrote a comment about it elsewhere in this discussion).
RPC is a low level API for which you have to set up and implement many parts that HTTP delivers out of the box. RPC probably not even has a significant performance advantage.