I do use a single cable in that it's just one cable coming from my monitor or dock. It's just one charging adapter in my bag. So generally speaking I am just plugging in a single cable to my monitor or carrying a single charger in my backpack. I'm not plugging in power, HDMI, network, and a USB hub separately every time I hop from one desk to another, just plug the one cable on the desk and it's good to go.

Sure, I'm not literally talking about a single cable I'm taking from one port to another port, but the fact I can just plug my laptop into my monitor and get all of that is awesome. And if I bought a good cable I could totally do that. The fact I'm able to charge all my devices off my laptop charger is awesome. The fact one could cheap out and buy a cable that wouldn't work with all the features of the monitor/laptop link doesn't make that less awesome. I just use the included cables with the docks or what not or make sure to buy a cable that does what I need if replacing/upgrading and it's not a problem.

You're still not convincing me the existence of cheap cables that can't do it all makes having several different cables and power adapters a better time. In one case you're absolutely forced to have them be separate every time, in another it's only that they're separate if you're buying cheap bullshit online from trash vendors.