said by OSUGoose:
Compare DSL and Cable, Where the DSL connection provided frequently has issues and throttles even youtube, yet the cable connection doesn't and provides a predictable consistent connection & speed regardless of content or time of day. The cost to provide the cable network will drop as there will be more rate payers to subsidize the costs for the installed network, while the DSL connection will degrade worse as there are less and less users to foot the costs. Now swap roles, and the argument remains.
What you said is far from true everywhere. There are plenty of places where the opposite is true and *DSL networks run fine without congestion and cable nodes are congested to crap. It really depends on the company and how the network is managed and if the components are upgraded appropriately.