The message of this psalm is for everyone – noble and common men, rich and poor. It applies to both the same.
Don’t fear those who have earthly treasures. All the money in the world can’t buy salvation or eternal life. (Neither can all the good works in the world earn someone salvation or eternal life).
Everyone dies no matter what their status in life.
Those who trust in themselves or in their wealth will remain in the grave for eternity. Those who trust in God will have eternal life.
It’s all right to have riches, but you must have the understanding of God to go along with them.