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.

Julian Groshaupt

This plugin adds some shortcodes to let you embed external content like youtube videos on your wordpress pages. Nothing new so far – why another plugin?
Well, this plugin puts emphasis on data protection. Before the content is loaded from an external area of responsibility (a third-party provider), the user must explicitly agree to the data transfer. In this way, the site operator is supported in designing his website in a data protection-compliant manner (taking into account the GDPR, among other things).
For the WPBakery Page Builder plugin, prefabricated blocks are also provided so that the shortcodes can be used directly.
Currently, embeddings of the following services are supported: 
* YouTube videos (Google) 
* Spotify (Artists, Albums, Tracks, Podcast Episodes) 
* Twitter (Single Tweet, User Timeline, Follow-Button, Mention-Button, Hashtag-Button)

Privacy Embed

Providing shortcodes to privacy-friendly embed external elements (like YouTube videos).

YEP: Optimize YouTube Embeds vs Privacy Embed