I'm also curious about this. Reinventing your own serialization and retransmission every time, instead of using proven technology does not sound like "decreasing" complexity. Same goes for using files and grep instead of databases in many cases.

It probably means that if you only need to ping a process from another one (no payload needed or only a handful of case expeceted) you don't have to deploy your last gRPC knowledge. cf. how daemons are managed on Linux