Question

How do the properties of long-lived stars compare to those of short-lived stars?

Answer 1

If we will base our answer on Hertzsprung diagram, we will see that mass and luminosity are directly related, which means, long lived stars begin their lives with more mass and a larger amount of hydrogen fuel, hence hydrogen is abundant before than now. They are more luminous during their main sequence lives.  Giant stars and supergiant stars have great masses, so, they have greater luminosities.