It will be better for environment and cheaper in terms of not having the need to buy tombstone. 
This will also increase the number of burial spaces available as well as options if the deceased do not want sea burial after cremation.

We would be providing nutrients for the trees when the deceased opt for this. This will allow Singapore to import less gardening soil.

It will potentially help NParks indirectly in the Million Trees Movement as the family members or friends of the deceased could already be participating in tree planting.