Why do car computers cost so much?

Did you actually have a point to all that babble? The world has resorted to everything being electronic. Even your fridge and dishwasher now has a mini computer in it and people still come here to ask what the codes are instead of looking in their manual. If it bothers you that much , then why not drive an older car? I still have a 75 El Camino That never fails to start and has no computer, gas mileage is not the same as a comparable 350 motor today but never needs a scan to tell me what is wrong.