The central message from the Great Gatsby is the domination/choice between wealth and love. Another message would be, live in the moment because the past cannot be changed to obtain the American Dream.
I believe this because:
Gatsby was wealth and Daisy was attracted to him years later due to the wealth he maintained
In my opinion, Daisy seemed like a gold digger.
When Gatsby died no one attended his funeral. Except for his dad, his mailman