One of the things which is making USB such a ubiquitous part of our modern world is its versatility. Most other connection protocols are single purpose in nature. By design, a charger charges and a data connection transfers data, for example. Yet USB electrical interfaces can do both of these things and can do them both at the very same time.
That is the magic of the USB system. It becomes truly universal in nature, since it can connect highly disparate systems and devices virtually without effort. Plug them in and they talk to each other. Thanks to the USB cord between them, they know what needs to be done, and it gets done without any cumbersome human interference.
Perhaps someday another protocol will succeed USB, but for now its reign as champion would seem to be a long one.
