Google ensures that this can be done with Drive instead of forcing people to use YouTube instead. So, the question is, how can we add captions to a Google Drive video with relative ease?

To add videos to a Google Docs document, you can insert a video via a link, add videos from Google Slides or insert a YouTube video into Google Docs.

Google Drive now lets you open videos directly in Google Vids to trim, caption, and add music without downloading files.