It doesn't matter what the default is. When you make a website you need to make it work for everyone, including people at the edges. That means delivering somet

It doesn't matter what the default is. When you make a website you need to make it work for everyone, including people at the edges. That means delivering something that works on a 'retina' display, which means using high resolution assets. Web devs should be building sites that deliver the best assets for the users device, but they often don't and just send the giant images and let the users browser scale them down to fit. Hence bigger websites.