I always figured Bun was the "enterprise software" choice, where you'd want to use Bun tools and libraries for everything and not need to bring in much from the broader NPM library ecosystem.
Deno seems like the better replacement for Node, but it'd still be at risk of NPM supply chain attacks which seems to be the greater concern for companies these days.
If you want to download open source libraries to be used in your Bun project then they will come from npm, at least by default. [1].
So it seems odd to say that Bun is less dependent on the npm library ecosystem.
[1] It’s possible to use jsr.io instead: https://jsr.io/docs/using-packages