0 dependencies No polyfill required No transpiling required. No config file etc. Will work on ie9+. Will play nice with other technologies/patterns you use in your page (es6 import/export etc.) Non-render blocking You can pause/resume the main thread Aware of document state (hidden, minimized etc.) Fine grained control on execution of all imported scripts. Uses Promises combined with requestAnimationFrame(rAF). Falls back to rAF on older browsers (ie etc). Supports nested/single dynamic imports. Your main thread will wait until a module finishes dynamically importing other modules. Supports then , catch phrases for dynamic imports. You can do things that you cannot do with ES6 directly
Taskq
Use async scripts everywhere, use them as modules, make your html its own config with 0 build time