> Actually, it would take one hour because you would use Poppler, and it would be cross-platform. It would also be faster than pdf.js.

I don't really know poppler. If there are Poppler bindings for the language you are developing in, I believe you that this is possible. This is only one use case though, I'm not sure you will find native libraries in your language for all features that VSCode can offer almost for free, like live markdown preview for instance.