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.

csv/tsv are alive & well for interorg data pipelines

But JSON uses floats, not integers.

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

Does it really? I assumed it used strings.