Using react-window

In real projects use a tested library: react-window (small, by the React team member Brian Vaughn), react-virtuoso or TanStack Virtual.

import { FixedSizeList } from 'react-window';

const Row = ({ index, style }) => (
  <div style={style}>Row #{index + 1}</div>   // style positions the row: always pass it
);

export default function BigList() {
  return (
    <FixedSizeList height={400} width="100%" itemCount={10000} itemSize={35}>
      {Row}
    </FixedSizeList>
  );
}