Questioning the Correctness of `List.map` Implementation

import { List, pipe } from "effect";

// prints:
// {
//   _id: 'List',
//   _tag: 'Cons',
//   values: [
//     [ 1, undefined ],
//     [ 2, undefined ],
//     [ 3, undefined ],
//     [ 4, undefined ],
//     [ 5, undefined ]
//   ]
// }
const test: List.List<[number, number]> = pipe(
    List.fromIterable([1, 2, 3, 4, 5]),
    List.map((x, index) => [x, index])
);
console.log(test.toJSON());

import { List, pipe } from "effect";

// Same thing but without pipe, idk why I thought it would be different
// prints:
// {
//   _id: 'List',
//   _tag: 'Cons',
//   values: [
//     [ 1, undefined ],
//     [ 2, undefined ],
//     [ 3, undefined ],
//     [ 4, undefined ],
//     [ 5, undefined ]
//   ]
// }
const l1 = List.fromIterable([1, 2, 3, 4, 5]);
const l2 = List.map((x, index) => [x, index])(l1);
console.log(l2.toJSON());