Yes it would cost a bunch, because many users suck at taking care of their cheap stuff, they don't have any sense of stress their mishandling puts on things, or because they're plain scammers. It's a risk companies and sellers don't need, especially small ones, and the benefit is that they can make stuff cheaper, sell stuff cheaper, and people can buy stuff cheaper. One of the many reasons median Americans enjoy a higher material standard of living than people in Europe.
Can you state 5 examples of products which you think are working great for more than a year and are cheap which you would buy without any warranty?
i am sure we all would be so happy to buy them.
I generally don't look at the warranties of products, so, literally everything I've ever bought except for my car.