Perhaps you feel that a funeral with a body is unnecessarily upsetting, morbid, even, especially if the person who has died was young. In that case you could organise a small funeral for close family and friends and then follow it with a celebration-of-life party at a venue of your choice to which everyone else is invited to eat, drink, listen to music and share happy memories.
A drawback here may be that those not invited to the funeral will feel that they can’t enter fully into the jollity of the life celebration because they never got a chance to express their grief and say goodbye first. They may even feel cheated or patronised. It can be hard to do the fun bit if you haven’t done the sad bit first. If people are hurting, you probably need to address those feelings before moving them on to happy memories. A death is exactly as sad as it is and there is nothing you can say or do to make it otherwise.
So a funeral without a body may feel like a diluted event. It may lack focus and substance and reality. It may lack power. A baby naming or christening wouldn’t be the same without a baby and a wedding wouldn’t be the same without the happy couple. If that logic extends to funerals, you need a body.