await/promises/etc mostly exist to solve the problem that JavaScript doesn't have threads so it can't wait for callbacks.
About JavaScript, many other languages have had async/await for a long time. I have no idea why JS made such a huge deal of promises, I guess they're better than the callback hell before. Of course, in most languages using async isn't nearly as important for performance because they have thread pools.
Some interfaces aren't and won't be asynchronous (like Linux file IO) so eventually JS will support proper threads and we can stop talking about how great asynchronous programming is (it isn't).
About JavaScript, many other languages have had async/await for a long time. I have no idea why JS made such a huge deal of promises, I guess they're better than the callback hell before. Of course, in most languages using async isn't nearly as important for performance because they have thread pools.
Some interfaces aren't and won't be asynchronous (like Linux file IO) so eventually JS will support proper threads and we can stop talking about how great asynchronous programming is (it isn't).