are polyfills solved just with core-js ( https://vived.io/fascinating-story-of-core-js-frontend-weekly-vol-125/ https://vived.io/fascinating-story-of-core-js-fr

are polyfills solved just with core-js ( https://vived.io/fascinating-story-of-core-js-frontend-weekly-vol-125/ https://vived.io/fascinating-story-of-core-js-frontend-weekl...), or is it because people don't support as many different browser engines these days?