其實callback hell其實你只要唔好係function裡面既argument位直接inline 寫anonymous function就避免到.
其實我覺得async await somehow到左最後developer(end user)手上都有點變質
async await 真正用處係避免cpu time佔左係blocking io上面. 例如話你curl 個網站要等, sync io 就會成粒cpu坐係到陪network interface等, 但async就可以free個cpu出黎, 係data寫入network interface既時候個cpu可以做其他野.
當然, 有機會因為其他野做耐左所以返黎await既function會返耐左, 呢個都係點解有部分很老的latency focused software會選擇while true等cpu空轉既原因. 但用左async await之後overall throughput就會高左好多, 因為cpu相比起network interface其實真係好得閒, 痾個尿返黎你network interface都隨時未準備好

