The feature should always provide some benefit to the user. This helps your team give priority to specific features that are going to provide real value and meaning to your users. And happy users means a successful product and a happy business.

The first example talks about hotel reservations. A better more complete version might state:

As a user, I want to reserve a hotel room close to the city center, so I don’t have to travel far every day.

It’s unlikely the user doesn’t have a specific location in mind for the hotel, whether they realize it or not. Adding the “why” part helps you come up with more creative solutions that might help the user, such as showing them hotels, based on their budget that are closer to the city center or to the airport. This might prevent the user having to leave the page and search the hotel addresses on Google maps and checking out distances. Otherwise, it might as well just be any other travel website that doesn’t provide a distinctly useful feature to the user.

The last user story example, however, is complete and useful to the design team; it shows exactly what the user wants – to be able to save past bookings and prevent extra data entry effort. It can also help come up with a better and more rigid acceptance criteria.