This plugin is no longer needed. WordPress has lazy-loaded images since version 5.5 and iframes since 5.7, using the browser’s native loading="lazy" — the same job, with no JavaScript.
It now works against you: replacing each image’s src with a placeholder stops the browser from discovering your largest image early, and that image is the one Core Web Vitals measures as LCP.
You can safely deactivate it. The one thing WordPress does not cover is lazy loading CSS background images. If you rely on that, keep it; otherwise there is nothing left for it to do.
This plugin, implementing “Lazy Load” technique, avoids download of the pictures and iframe that are not displayed on the screen (for example: images in the bottom of the page) until the user will display them. This improves load speed of page and save the bandwidth.
Configurations are not required! You just have to install it and after the plugin does it all, none further action it’s required.
This plugin is very light: only 5 kb.