There are many reasons to sing, a few are mentioned below:

It is fun;

It is a sociable activity through which you can meet new people;

Some people find singing in a group with other people an uplifting experience;

No matter what style of music you prefer it is possible to join in as a vocalist;

Breathing techniques used in singing can help conditions such as asthma;

Singing is harder work than it appears so it is a great way to improve your aerobic fitness and core muscle strength;

By training your singing voice you will be able to strengthen your speaking voice which can be useful if your job involves public speaking or if you are a professional voice user such as a teacher.

Finding your singing voice is a path to self awareness and self development;

Music-making will develop your collaborative skills and your ability to multi-task as you have to be able to sing your own line whilst listening and responding to how other members of the group are performing.