This really has nothing to do with the inevitability of death. Death is inevitable, however there is a difference between a child dying and an elderly person dying. A child has potential, they have not lived their lives. A child has not actually lived the full basic human experience, they havent had a crush, or fallen in love or married or had children or had any great successes or failures or close friends or anything, these things everyone does. An older person has, they are not a pure soul who hasnt experienced life. After 70 years you can be sad for the individual passing but happy that they have experienced life. This is why when a parent has a child they arent sad that their child will die in 80 years, but are devasted if they die at a week. The child never even had a chance. When you actually have a child, its an emotional and fulfilling experience, and to have that torn out so early is damaging.
From an empathy and emotional pov these things are so extemely basic and foundational aspects of being a human, a 10 year old from any culture on earth can undersrand this with no difficulty. And any person with even a passing familiarty with logic, ethics or philosophy will dismiss you as being earnest. Which is why people are assuming you are a troll.