Yes, Because they give caring friends and family closure. However, Most funerals are a huge waste of money that could be spent on more worthwhile things. Simple funerals are always the best. Read the good book THE AMERICAN WAY OF DEATH for an analysis of how funerals are often ripoffs of the family.
I firmly believe that funerals serve not only as moments to garnering or rendering emotional support from bereaving relatives of the deceased, But also as a means of offering our blessings unto the spirit of the deceased.
In addition, Funerals also happens to serve an important role into dedicating moments of introspection into pondering on the lives of those who have had to forsake their bodies voluntarily/involuntarily and sojourn into the afterlife.