Lite YouTube Embed를 이용하면 기존 iframe 보다 약 224배 더 빠름

예시

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/lite-youtube-embed/src/lite-yt-embed.css " />  
<script type="module" src="https://cdn.jsdelivr.net/npm/lite-youtube-embed/src/lite-yt-embed.js "></script>  
<lite-youtube videoid="dQw4w9WgXcQ"></lite-youtube>  

https://github.com/paulirish/lite-youtube-embed