WASM-compiled code might completely replace javascript, being faster at all stages: loading, parsing and execution. That's probably the point he was making.
The majority of news, social media, video, media sites, message boards, online games and web apps fit this description. I'd wager that 95%+ of websites produced by a paid professional today are in this category. Unfortunately no, I don't have data to back this up, only my perception as a web developer.
[1] due to relying on a module system, es6 transpiler, etc
I also don't consider a website serving machine-generated javascript to be a "compiled application" analagous to a C, Flash or Java binary (whereas WASM would be,) but almost every time I try to go down the "javascript is not machine code or bytecode" rabbithole, I get downvoted to oblivion.