YouTube and other video content is invisible to search engine crawlers.
By adding relevant metadata, such as titles, tags, and descriptions, it makes video content visible to search engines and therefore, easier for potential viewers to find, too.
When your video is easier to find, your number of views, duration of views, video engagement, and video likes increase. In other words, you increase the performance of your YouTube videos. As an added bonus, videos that perform well can improve website search ranking and domain authority, resulting in additional traffic.
However, to be most effective, metadata should be informed by thorough research and evaluated through reporting and analytics.
Increasing Video / YouTube SEO performance
Video and YouTube SEO optimizations include a baseline report, metadata implementation or revision, and a final report for comparison.