Shipping support for both a text format and a binary format directly in the browser is in some ways the worst of both worlds. If both are implemented natively,

Shipping support for both a text format and a binary format directly in the browser is in some ways the worst of both worlds. If both are implemented natively, you get double the attack surface at the ingestion layer. If the text format is supported by compiling to the binary format (or vice versa) using WASM that happens to ship with the browser, it will probably be slow (whereas ingesting a text format directly seems pretty fast).