At scale, the performance gains can be dramatic. For example, moving a json web service to CBOR, I was able to squeeze 15% more throughput out of existing hardware. When you’re dealing with hundreds, if not millions of requests per minute this can be financially prudent.
In my case I was using CBOR, not protobuf. The effect could be similar though when moving from json to protobuf. You get a much more efficient serialization and deserialization. This reduces CPU demand on server side for sending response payload and for client to receive the payload.
