You are right, of course. We don't need to produce surpluses, like sturdy waterproof housing, wide selections of cheap foods, fast methods of transport, electricity and all it entails, and things like computers and internet. We can all survive without them, producing only the minimum amounts we need to survive, as we did for hundreds of thousands of years.
But it's nice to have those things, anyway, especially since then you can sit in the safety of your home, warm and well fed, and spend your time on a computer, arguing about how we don't need any of these things, as opposed to busting your ass 4am to 9pm every day to grow food, or chasing down antelope, with not even enough time to say hi to your neighbor