Yeah maybe a bit harsh. But the point is if you are looking for that kind of performance, I don't see why you wouldn't send binary data and then unpack it as needed.
If you control both ends of the pipe, then sure. But for better or worse, large chunks of infrastructure expect to send or receive JSON.
But JSON uses floats, not integers.
Does it really? I assumed it used strings.
javascript uses floats as its own default numeric data type; but other languages do have integers, and might want to convert those integers into a JSON (string) representation
csv/tsv are alive & well for interorg data pipelines
Because maybe the choice of serialization format isn't under your control?