I’ve been on a similar hunt. My devices are littered with copies of videos that were shared via iMessage, WhatsApp, and other means. Each of these apps then store the copy locally which then gets backed up in iCloud.
Unfortunately I haven’t found a way to automatically delete all the videos/photos that I send which still have the original in the photo stream. It would be awesome to be able to automate that.
This isn't perfect, nor automated, but you can search the Messages app for photos/videos and delete them all. Assuming you've saved them already, this should clear up some iCloud space.
Unfortunately I haven’t found a way to automatically delete all the videos/photos that I send which still have the original in the photo stream. It would be awesome to be able to automate that.