One issue with Protobufs is they do not always enable optimal performance (latency, power). Better than JSON but worse than some others. Compared to MessagePack

One issue with Protobufs is they do not always enable optimal performance (latency, power). Better than JSON but worse than some others. Compared to MessagePack, Protobufs require a schema, which is not always convenient. Compared to Cap'n Proto, Protobufs are less CPU efficient. Trade offs all around.