I don't see your point? Nodejs is installed in a custom directory and not added to PATH. It is used by Zed for providing npm support for extensions, and other things. I'm not a Zed developer so I don't know exactly.
It doesn't prevent you from using deno or bun in any way.
Nobody is arguing that you should never depend on anything and create everything yourself, but adding a dependency for literally a one liner function is awful. Like one of the Go proverbs goes, a little copying is better than a little dependency.