I guess you could use the same argument to say you’re buying less when you buy your laptop. It’s just arbitrary data I/O through USB with the software level interpreting it. They don’t have to ship a DAC or wifi radio or… whatever you call the component that’s part of a GPU that converts to HDMI, instead they offload that to the dongle or peripheral. In effect your device is just slowly being whittled down to a processor to USB bridge.