There are different moons in the solar system that are known to come with different atmospheres. The atmospheres of the different moons are different but out of all of them, Titan is the only one with a significant atmosphere. The atmosphere of Titan is nitrogen-rich.
It also has some clouds which are similar to the type of atmosphere that can be found in different planets. These are just some of the reasons why a lot of scientists are so excited to look into this planet further and to find out more details about it. Only time will tell if things would change in the long run.