I may change my tune six months from now, but part of the problem I see is that new people getting into React are told to not learn redux to "keep things simple." While it's a little bit of a pain to set up, redux (+ redux-thunk) ultimately reduces the amount of complexity and magic considerably.

Of you can write stateless functional components and have async and not use them, but the disadvantages of components without lifecycle methods appear much greater if you're just using vanilla React.