Our best practices are killing mobile web performance
Why isn't there a way for devices to indicate to a server if they are on a slow or data-capped connection?It seems like "responsive" web design is based entirely around the size or pixel-density of a device's screen. But why can't the experience respond to the speed of a user's connection, or the amount of data the user can afford to download?My phone already knows I have a hard data cap when I'm off wifi. Why can't it include a field in its request to every web server indicating I would like the smallest amount of data possible, and then properly configured servers can respond by omitting large images, videos, font files, etc. We have srcset for images, but AFAIK choosing which image to use is still based on screen size rather than bandwidth. And we need to get beyond srcset - as a content creator, I want to be able to mark some images and other heavy resources as optional, so I don't reference to them at all to bandwidth-sensitive devices.