With "type": "module" there's very few reasons to do dual compilation unless you have very conservative downstreams that hate promises and async/await, and even then there's mitigations now (sync `require()` of async ESM).

It's been a while since I've had a trouble importing an upstream CommonJS library. Often it is easy enough in the rare cases where upstream is particularly old/gnarly you can vendorize an ESM build with rollup or esbuild.

That said, CommonJS is also now a strong maintenance signal for me and if a library doesn't have recent ESM builds I start to wonder if it is at all well maintained and not just a pile of tech debt to avoid. JSR has started becoming my first place to search for a library I need, ahead of NPM, because of JSR's focus (and scoring systems) on ESM first and good Typescript types.