The sad part is, for many laptops, a lot of those extra processes are needed.

My laptop, for instance, needs extra processes running to enable the strip of buttons that controls the speaker volume and the wireless on/off functions, as well as the special function keys on the keyboard. Another process is needed to govern its fingerprint reader, another for its built-in noise-cancelling microphone, and yet another for its touchpad.

If I had wiped the laptop when I bought it, those things would all have stopped functioning and I would have needed to scrounge their drivers and hope for the best.