I would avoid rebuilding your application in Apps. The Glide Apps product is already Glide’s legacy solution, all applications are to be moved over and built on Glide Pages moving forward. It is likely that Apps will be renamed Legacy and Pages renamed Apps. So stick to the new Glide Apps (=Pages).
If you want the exact comments component in Pages as in Apps, right now it is not available. But it could be soon.
Theoretically, you could allow users to add comments to a video item, each comment would be added to a Comments table and you would create a multi-relation from your Videos table to Comments table to display the right comments under each video. Your row count could blow up quickly: 100 videos and 10 comments per video, that would be 1000 rows of comments. This idea is not very scalable.
The comments component can be built by hand. But realistically, I don’t think the comments component should be built by hand.