Webamator

YouTube iframe embeds often load many unnecessary resources, which slows down your page. YEP: Optimize YouTube Embeds is a lightweight WordPress plugin that replaces YouTube iframes with a clickable preview image. 
The actual video loads only when the user clicks the play button, improving page load times and reducing initial page size.
<h3>External services</h3>
This plugin uses the external YouTube thumbnail service (https://i.ytimg.com) to display preview images of YouTube videos. 
When a page with a YouTube embed is loaded, the plugin requests the thumbnail image directly from YouTube servers. 
No personal data is sent from your site to YouTube, only the video ID (already public in the YouTube URL).
Privacy Policy: https://policies.google.com/privacy 
Terms of Service: https://www.youtube.com/t/terms

YEP: Optimize YouTube Embeds

Short Description: Load YouTube videos faster by replacing iframes with a preview image; the video plays only when clicked play.

Luis Ruiz

Just by installing the plugin, we will deactivate the related videos that are displayed at the end of a YouTube Video.
No configuration is required, it applies to all videos that are inserted into the Gutenberg YouTube block.

Bubuku Disable Related Videos

Plugin to disable related YouTube videos that appear at the end of the video when you embed it in Gutenberg

YEP: Optimize YouTube Embeds vs Bubuku Disable Related Videos