What are the benefits of losing all emotion......

A lot:

You don't fall in love- less drama in life.

You don't need to make happy to anyone. 

Somebody is trying to humiliate you? - You don't give a f***
Friends forgot your birthday? - Never mind, they still are your friends
Somebody is trying to please you for his own good? - Never falling for that trap
Somebody is showing off his lavish lifestyle to make you jealous?-just ignore

Apart from this you get rid of unnecessary obligations.

In short life becomes easy and blissful