They're a step towards it, but they don't really solve the callback after callback on their own. You need something like a ->get() or await on them to be able

They're a step towards it, but they don't really solve the callback after callback on their own. You need something like a ->get() or await on them to be able to serialize the flow of things to completely solve that. But that encapsulation of success or failure does do wonders for helping the swallowing of exceptions, by basically wrapping the async operation in a try/catch that carries it over for you.