It scoffs at our medicines and surgeries and diets and vitamins and exercise programs. When all is said and done, rocket scientists die. Nobel prize winners die. The rich die and the poor die. The good die and the evil die.
Computer programmers die.
And preachers die. Death is not subject to man. And therefore nothing is ultimately subject to us, because it is only a matter of time till it will all be taken away from us, and what we thought we had mastered will be ripped out of our hands. That's what this writer is painfully aware of at the end of verse 8. The Psalm says that man has a great destiny as the ruler of the creation.