I don't think this adds much. The important thing is that your logic runs in the database--how the logic is ultimately exposed is up to you. We did a java app server calling SPs over JDBC with generated, typed bindings and this worked great. You'd have to write a similar tool to generate a gRPC server, but the logic would still be SPs in the database. That's the part that sucks for devs; the bindings are ultimately a detail.