async is a great feature if you use it from square 1. If you start with a legacy codebase using callbacks and try to port it incrementally to async, you're gonna have a bad time. Otherwise, it's definitely a feature
Yeah upgrading a legacy codebase that uses callbacks is not fun, but if the callback functions follow the Node error first value second convention, then it's a little bit easier because you can just use `util.promisify` to convert them to promises in Node. There's also the new Promise.withResolvers method which helps a bit too [1].
[1] https://github.com/tc39/proposal-promise-with-resolvers