No they aren't, if there's congestion in the area then that exchange will put traffic management in place.
LOL do you even know what congestion means? Too many people subscribed in your area.
Yet whenever I try to stream football on a night it's completely unwatchable even at 1000kbps.
Just because something is capable of so much bandwidth doesn't mean that's what the end user is getting, in fact we'll be far from those perfect figures.
As Neil McRae said I can safely tell you that we have _way_ more bandwidth than is in use to the points where we interconnect with network providers.
If that was the case then there'd be no issues with streaming, gaming or anything. There's clearly chokepoints in the network, the bandwidth figures they measure are usually in perfect circumstances.