The responsive images standard doesn't try to deliver the best image for your network but the best image for your display. I don't know where things stand regar

The responsive images standard doesn't try to deliver the best image for your network but the best image for your display. I don't know where things stand regarding browsers sharing network quality information, it's harder and may have privacy implications. You have control of your browser to improve your experience in poor network situations, you could set it to not load images by default or use your browser's responsive design mode to make it lie about your screen's pixel density.