The only mentioned benefit seems to be privacy.
Apparently it prevents this auto embedding:
YouTube injects their video link directly in its RSS feeds in a way that will cause some RSS Readers to automatically embed the YouTube video
But it is just a media link. It isn't like YouTube is doing something nefarious. This are just doing RSS (somewhat) like intended. If your feed reader renders these links without any confirmation it is an issue that will affect all feeds and you should change the settings on your feed reader.
In general I like openness providing feeds for sites that don't have them but this seems a little pointless. I guess it is basically a proxy service that hides your IP at this point?