Comment by hiccuphippo

You mean why not implement these things directly in node instead of a separate runtime? There's significant differences between runtimes. Node uses V8 while Bun uses JavascriptCore. Node uses C++ and Bun uses Zig. I'd guess it would be very difficult to land these changes in Node.

But Node now will have some catch up to do. It is already adding support for running Typescript without transpiling it to js first and that's because Bun and Deno provided it first and people saw it was a good idea. Maybe Node will add these things in the future.