It seems to me that with WASM, it's easier than ever to have good cross platform and performant implementations for dealing with pdf and many other file formats

It seems to me that with WASM, it's easier than ever to have good cross platform and performant implementations for dealing with pdf and many other file formats in a sane way. There is a lot of open source software out there that probably already can be compiled to run in a browser with WASM.