Html <img> and <picture> elements already have the ability to serve larger or smaller images (srcset) based on your browser's perception of your network perform

Html <img> and <picture> elements already have the ability to serve larger or smaller images (srcset) based on your browser's perception of your network performance. I agree with the other comment here replying to you. In the olden days people had to explicitly link to larger content. Isn't that was AMP does anyway?