Actually, this is horrifying to think about. I'll concede that JSON is the answer for most public HTTP APIs, but it's also used for tons of internal IPC. The energy that could be saved with more efficient alternatives is likely substantial.
While sending data between C++/Go/Java processes as JSON is a waste, when one part is a scripting language, JSON can be more efficient than alternatives.
Recently I benchmarked extension API in Chromium. Those can send arbitrary data from C++ main browser process to the renderer process running extension JS code. Internally API use a binary format plus they verify that the data matches API scheme.
It turned that for complex data writing the data to JSON on C++ side, sending the string using the same API and decoding that in JS was faster. The code to read binary data and convert that to JS plus the scheme verification was not optimized in Chromium, while JSON decoder was.
i suspect you mean pragmatically for humans, since there is support for it in most libraries. but for concise equivalent marshalling, i wonder if YAML or TOML etc would be faster to parse. Or Amazon's Ion superset of JSON.
