Ask HN: Nowadays, should I make my js use callbacks, promises, or other?

Say I'm making javascript library that needs to do some asynchronous work. What is the current modern best practice?

getusermedia and jquery use callbacks, but it seems like that fell out of favor a while ago (or have callbacks come full circle and are preferred again?).

WebCrypto uses promises. Is that now what everyone is using for new libraries, or have people grown tired of promises?

XMLHttpRequest uses listeners (or whatever they are called: .onreadystate, etc.) which I guess are kind of like callbacks or events? Has that technique started to gain favor again?

Inter-iframe communication (postMessage) and bootstrap (for CSS transitions) use event listeners. Are events now a better way to signal when an asynchronous task is done?

I haven't kept up with all the latest preferred way to do this.