If you use them, platforms like Soundcloud have features where during the playback of a song, you can see timestamps throughout the progression where users have left comments. This can be helpful if some users might comment about a part of the song they like.
YouTube does allow users to leave comments that include the timestamp, but sometimes you have to go looking for it, and not all users bother to do it, but that could change. According to a YouTube support document, the company is testing a timestamp button that will allow users to leave comments at a particular point in the video.
YouTube says, “We’re testing out an easier way to add a video timestamp tied to the exact moment you’re watching when commenting on a video. People in the experiment will see a new icon as they’re writing a comment that they can tap to automatically add the current time of the video (without having to manually enter it themselves!).”
YouTube has been making its videos more contextual, and this is a part of that endeavor. They also recently announced that they will be testing out the ability for AI to help automatically generate chapters so that users can skip ahead to other areas of the video.
Source Ubergizmo