In my experience, you may encounter issues when you depends on pure esm package and cjs-only packages. IMHO, it is still useful to publish a cjs fallback.
You may encounter issues with mixed packages too, actually a lot more issues given that people expect `module.exports = ` and `export default` to be equal but are not.
Just save yourself some headache and publish either ESM or CJS, not both.
Just save yourself some headache and publish either ESM or CJS, not both.