Using image CDNs
Another approach is to run your images through an optimizer that you install onto your computer and run as a GUI. For example, with ImageOptim you drag and drop images into its UI, and then it automatically compresses the images without compromising quality noticeably. If you're running a small site and can handle manually optimizing all images, this option is probably good enough.
Squoosh is another option. Squoosh is maintained by the Google Web DevRel team.
Consider using a module that automatically optimizes and reduces the size of images uploaded through the site while retaining quality. Also, ensure you are using the Drupal's built-in Responsive Image Styles (available in Drupal 8 and above) for all images rendered on the site.
Consider using an image optimization plugin that compresses your images while retaining quality.
Consider using a third-party Magento extension that optimizes images.
Consider using an image optimization WordPress plugin that compresses your images while retaining quality.