Polyp polyfills all stable web platform features (anything in core-js/stable that's shipping in at least one browser) while only addding about 4 kB of feature detection code to your bundle. This works because Polyp dynamically imports polyfills only if an out-of-date environment is detected. Polyp loads polyfills in stages. Up-to-date browsers won't load polyfills at all, and browsers that are just a few versions behind won't need to load every polyfill.
npm i polypimport polyfillsReady from "polyp";
polyfillsReady.then(() => {
// Use new web features :D
});