Personally I much prefer Deno as it's also doing a lot more work to unify the backend and frontend JS APIs.

I would too ... but not as the winning competitor.

For their first year two of existence, bun tried to do npm, but better. For the first year or two of their existence, Deno tried to reinvent npm.

The key result is that after that first year or two Deno had to walk back their decisions, to create a Node-ecosystem-compatible tool .. and as a result, they're now significantly behind bun (at least by all metrics I've seen).

I would mention Node as the main competitor. It isn't moving as vast as the VC-backed ecosystems are but its future is a lot more assured.