nextjs/no-unwanted-polyfillio Correctness
What it does
Prevent duplicate polyfills from Polyfill.io.
Why is this bad?
You are using polyfills from Polyfill.io and including polyfills already shipped with Next.js. This unnecessarily increases page weight which can affect loading performance.
Example
javascript
<script src='https://polyfill.io/v3/polyfill.min.js?features=Array.prototype.copyWithin'></script>
<script src='https://polyfill.io/v3/polyfill.min.js?features=WeakSet%2CPromise%2CPromise.prototype.finally%2Ces2015%2Ces5%2Ces6'></script>