Generators are useful as custom iterators...

generators.js

/*
 * Provides a powerful tool for implementing custom iterators and 
 * simplifying asynchronous workflows. Generators make it easier to 
 * handle complex iteration logic and asynchronous processes, leading 
 * to more readable and maintainable code. They can also be used for 
 * tasks like managing asynchronous operations in a more 
 * straightforward, linear fashion.
 */
function* objectEntries(obj) {
    for (let key of Object.keys(obj)) {
        yield [key, obj[key]];
    }
}

const user = { name: 'John', age: 30, city: 'New York' };

for (let [key, value] of objectEntries(user)) {
    console.log(`${key}: ${value}`);
}
// name: John
// age: 30
// city: New York