To be fair, if you chose gRPC for performance, but then end up using JSON for most of your traffic, perhaps you picked the wrong tool.

I don't think generally people want to have JSON accepted to use in their production workloads. More for development, testing, that kind of thing. Being able to just curl your service makes a huge difference.

It always starts that way, then people demand JSON everywhere ("why not?"), then they complain when things get too slow or when the OOMs begin to appear. :-)