Speed is how many measure improvement of fitness, how one can compare one's level of fitness. I don't obsess over speed, but it is an indicator of some things.
On flat ground I can keep up with or drop a lot more people than I can in the hills, but I am over 200 pounds.
I can do a hilly century any weekend, but there are 60+ riders in my club and even 55+ women who can do the rides faster.
To answer the poll, it would be more fair if we could compare to others who do a similar amount of riding.