because USB is serial, and parallel is parallel. So every bytes has to be sent in parallel after you made sure you signal correctly they are ready the directio

because USB is serial, and parallel is parallel. So every bytes has to be sent in parallel after you made sure you signal correctly they are ready the direction of communication... So, it makes a lot of trouble. USB is still one of the biggest mistake of computer hardware where a supposed simplicity for the user comes at the price of an clumsy complex unsecure spaghetti layer of abstractions in order to prevent small hardware makers to compete. A bus should not care of the class of the device on the bus. A simple handshaking protocol with a simple fixed size identifier handled by something like IANA could be enough. It could also be just declarative avoiding bad surprises (well I still don't understand why my computer sees 3 USB keyboard at bootup and what my devices can do). You have 1 device on the bus, you load explicitly the driver, avoiding functionalities you don't wish to work. USB is hardly auditable, while a multi input oscilloscope is enough to see what happens on a // bus and debug analyze... The certification process is a pain. The HW manufacturers do what they want and patch the protocol in ways that are wtf. And just look at the dozens of cable to convince yourself the U in USB is not for Universal anymore, but rather Unconsistent. USB is almost DRM by obfuscation for the profit of shitty hardware manufacturers. Long live to USB-C, long live to the future of computer where obsolescence is programmed every 5 years, while some electronic have a life expectancy of decades (industry, aeronautic, medical systems, expensive labs systems, weapon systems, traffic signalisation, nuclear/energy equipment)...