WHEN CAN WE CHANGE USERNAMES??

so snapchat is snapchat. whatever its just any other social media blah blah blah. BUT TELL ME WHY WE CAN BE A DOG, HAVE A DANCING HOTDOG, STALK OUR FRIENDS BUT NOT CHANGE OUR USERNAMES???? I MADE SNAPCHAT IN 5th GRADE AND I WILL FOREVER REGRET MY USERNAME WHEEENBNNNN CAN WE CHANGE THEM

dathotdogdude about Snapchat, v10.14.1.0