Given Promises and callbacks have always been pervasive in JS—that it’s always been heavily asynchronous—I can’t imagine thinking async/await was a mistake. It’

Given Promises and callbacks have always been pervasive in JS—that it’s always been heavily asynchronous—I can’t imagine thinking async/await was a mistake. It’s a drastic ergonomic improvement over both, and it also drastically improves debugging and error stacks. Adding it to a language where IO is typically blocking with other ergonomic concurrency mechanisms, that I can imagine being somewhat controversial. It would be good if async weren’t infectious, but as a sibling comment said that was already the case with Promises and callbacks. It would maybe also be better if concurrency was the default behavior and keeping a reference to a promise was the explicit syntax, but I could see downsides to that. It potentially hides/encourages excessive use of expensive calls. And implicit concurrency is a potential source of many bugs.