I’ve been playing around with streams and I cannot explain the following behaviour:

import * as fs from 'fs/promises';
import * as csv from 'csv';

const MERCHANT_NAME = 'lm';

const run = async () => {
    const fileContent = await fs.readFile('./input', { encoding: 'utf-8'});
    const parser = csv.parse(fileContent);
    const output = parser.map(
        ([id, pm, psp]: [string, string, string]) => ({
            merchantName: MERCHANT_NAME,
            providerName: psp,
            paymentMethod: pm,
            userId: +id,
            data: null,
          }),
    );

    const userIdsToken = await output
    .map((record) => record.userId)
    .reduce((acc, cv) => (acc === '' ? acc + cv : acc + ',' + cv), '');

    console.log('output.destroyed', output.destroyed); // true
    output.forEach(r => console.log(r)); // ain't going to print out nothing...

    const output2 = parser.map(
        ([id, pm, psp]: [string, string, string]) => ({
            merchantName: MERCHANT_NAME,
            providerName: psp,
            paymentMethod: pm,
            userId: +id,
            data: null,
          }),
    );
    console.log('output2.destroyed', output2.destroyed); // false
    output2.forEach(r => console.log(r)); // ain't going to print out nothing...
}

run();

There’s a stream called output of type internal.Readable which is destroyed when userIdsToken is computed. Then I try creating another stream output2 which is not destroyed but still output2.forEach(r => console.log(r)) does not print anything.
What is happening and how to fix it?