Well data bandwidth is sold that way but its the only way it can be done.
If you pay $40/month for internet access at your house, and you are the only one on that trunk then speed would never change
As provider added more subscribers on that trunk/hub, all paying the same $40/month, you could get your "comparison"
And at full load(many subscribers on-line) speed would be reduced until Provider added more Hubs to the area