That wasn't the reason promises were introduced. An XMLHttpRequest can be synchronous which is Bad™ and that is something explicitly not allowed by the Promise/

That wasn't the reason promises were introduced. An XMLHttpRequest can be synchronous which is Bad™ and that is something explicitly not allowed by the Promise/A+ spec which means it will never be something that fetch() could do. The advantage of promises is that they can be `await`ed in the context of an `async` function which takes a lot of the cognitive load off of the developer.